CWE-348

CasaOS is an open-source Personal Cloud system. Due to a lack of IP address verification an unauthenticated attackers can execute arbitrary commands as `root` on CasaOS instances. The problem was addressed by improving the detection of client IP addresses in `391dd7f`. This patch is part of CasaOS 0.4.4. Users should upgrade to CasaOS 0.4.4. If they can't, they should temporarily restrict access to CasaOS to untrusted users, for instance by not exposing it publicly.

Termix is a web-based server management platform with SSH terminal, tunneling, and file editing capabilities. The official Docker image for Termix versions 1.5.0 and below, due to being configured with an Nginx reverse proxy, causes the backend to retrieve the proxy's IP instead of the client's IP when using the req.ip method. This results in isLocalhost always returning True. Consequently, the /ssh/db/host/internal endpoint can be accessed directly without login or authentication. This endpoint records the system's stored SSH host information, including addresses, usernames, and passwords, posing an extremely high security risk. Users who use the official Termix docker image, build their own image using the official dockerfile, or utilize reverse proxy functionality will be affected by this vulnerability. This issue is fixed in version 1.6.0.

Apache HTTP Server 2.4.53 and earlier may not send the X-Forwarded-* headers to the origin server based on client side Connection header hop-by-hop mechanism. This may be used to bypass IP based authentication on the origin server/application.

Traefik is a golang, Cloud Native Application Proxy. When a HTTP request is processed by Traefik, certain HTTP headers such as X-Forwarded-Host or X-Forwarded-Port are added by Traefik before the request is routed to the application. For a HTTP client, it should not be possible to remove or modify these headers. Since the application trusts the value of these headers, security implications might arise, if they can be modified. For HTTP/1.1, however, it was found that some of theses custom headers can indeed be removed and in certain cases manipulated. The attack relies on the HTTP/1.1 behavior, that headers can be defined as hop-by-hop via the HTTP Connection header. This issue has been addressed in release versions 2.11.9 and 3.1.3. Users are advised to upgrade. There are no known workarounds for this vulnerability.

Nimble is a package manager for the Nim programming language. In Nim release versions before versions 1.2.10 and 1.4.4, "nimble refresh" fetches a list of Nimble packages over HTTPS by default. In case of error it falls back to a non-TLS URL http://irclogs.nim-lang.org/packages.json. An attacker able to perform MitM can deliver a modified package list containing malicious software packages. If the packages are installed and used the attack escalates to untrusted code execution.

Nimble is a package manager for the Nim programming language. In Nim release versions before versions 1.2.10 and 1.4.4, "nimble refresh" fetches a list of Nimble packages over HTTPS without full verification of the SSL/TLS certificate due to the default setting of httpClient. An attacker able to perform MitM can deliver a modified package list containing malicious software packages. If the packages are installed and used the attack escalates to untrusted code execution.

A vulnerability was found in mod_wsgi. The X-Client-IP header is not removed from a request from an untrusted proxy, allowing an attacker to pass the X-Client-IP header to the target WSGI application because the condition to remove it is missing.

The Web Application Firewall plugin for WordPress is vulnerable to IP Address Spoofing in versions up to, and including, 2.1.2. This is due to insufficient restrictions on where the IP Address information is being retrieved for request logging and login restrictions. Attackers can supply the X-Forwarded-For header with with a different IP Address that will be logged and can be used to bypass settings that may have blocked out an IP address or country from logging in.

Fabio is an HTTP(S) and TCP router for deploying applications managed by consul. Prior to version 1.6.6, Fabio allows clients to remove X-Forwarded headers (except X-Forwarded-For) due to a vulnerability in how it processes hop-by-hop headers. Fabio adds HTTP headers like X-Forwarded-Host and X-Forwarded-Port when routing requests to backend applications. Since the receiving application should trust these headers, allowing HTTP clients to remove or modify them creates potential security vulnerabilities. Some of these custom headers can be removed and, in certain cases, manipulated. The attack relies on the behavior that headers can be defined as hop-by-hop via the HTTP Connection header. This issue has been patched in version 1.6.6.

A Use Of Less Trusted Source [CWE-348] vulnerability in Fortinet FortiPortal version 7.0.0 through 7.0.6 and version 7.2.0 through 7.2.1 allows an unauthenticated attack to bypass IP protection through crafted HTTP or HTTPS packets.

Client use of server error message in PostgreSQL allows a server not trusted under current SSL or GSS settings to furnish arbitrary non-NUL bytes to the libpq application. For example, a man-in-the-middle attacker could send a long error message that a human or screen-scraper user of psql mistakes for valid query results. This is probably not a concern for clients where the user interface unambiguously indicates the boundary between one error message and other text. Versions before PostgreSQL 17.1, 16.5, 15.9, 14.14, 13.17, and 12.21 are affected.

OpenRefine is a free, open source tool for working with messy data. Prior to version 3.8.3, the `export-rows` command can be used in such a way that it reflects part of the request verbatim, with a Content-Type header also taken from the request. An attacker could lead a user to a malicious page that submits a form POST that contains embedded JavaScript code. This code would then be included in the response, along with an attacker-controlled `Content-Type` header, and so potentially executed in the victim's browser as if it was part of OpenRefine. The attacker-provided code can do anything the user can do, including deleting projects, retrieving database passwords, or executing arbitrary Jython or Closure expressions, if those extensions are also present. The attacker must know a valid project ID of a project that contains at least one row. Version 3.8.3 fixes the issue.

Unitronics Unistream Unilogic – Versions prior to 1.35.227 - CWE-348: Use of Less Trusted Source may allow RCE

The Limit Login Attempts (Spam Protection) plugin for WordPress is vulnerable to IP Address Spoofing in versions up to, and including, 5.3. This is due to insufficient restrictions on where the IP Address information is being retrieved for request logging and login restrictions. Attackers can supply the X-Forwarded-For header with with a different IP Address that will be logged and can be used to bypass settings that may have blocked out an IP address or country from logging in.

Serilog before v2.1.0 was discovered to contain a Client IP Spoofing vulnerability, which allows attackers to falsify their IP addresses by specifying an arbitrary IP as a value of X-Forwarded-For or Client-Ip headers while performing HTTP requests.

The Hide My WP Ghost – Security Plugin plugin for WordPress is vulnerable to IP Address Spoofing in versions up to, and including, 5.0.18. This is due to insufficient restrictions on where the IP Address information is being retrieved for request logging and login restrictions. Attackers can supply the X-Forwarded-For header with with a different IP Address that will be logged and can be used to bypass settings that may have blocked out an IP address from logging in.

Use of Less Trusted Source vulnerability in Apache APISIX. Attacker can take advantage of wolf-rbac plugin under default configuration to potentially pollute logs with spoofed identity information and exploit IP based access control rules. This issue affects Apache APISIX: from 1.2.0 through 3.16.0. Users are recommended to upgrade to version 3.17.0, which fixes the issue.

The Brizy Page Builder plugin for WordPress is vulnerable to IP Address Spoofing in versions up to, and including, 2.4.18. This is due to an implicit trust of user-supplied IP addresses in an 'X-Forwarded-For' HTTP header for the purpose of validating allowed IP addresses against a Maintenance Mode whitelist. Supplying a whitelisted IP address within the 'X-Forwarded-For' header allows maintenance mode to be bypassed and may result in the disclosure of potentially sensitive information or allow access to restricted functionality.

Hermes WebUI before 0.51.307 contains an authentication bypass vulnerability that allows unauthenticated remote attackers to circumvent local-origin IP restrictions on onboarding endpoints by supplying a spoofed X-Forwarded-For header with a loopback address. Attackers can exploit this bypass to perform server-side request forgery against internal services including cloud metadata endpoints, overwrite LLM provider configuration and API keys with attacker-controlled values, or initiate OAuth device-code flows to obtain persistent access tokens stored in auth.json.

Szafir SDK Web is a browser plug-in that can run SzafirHost application which download the necessary files when launched. In Szafir SDK Web it is possible to change the URL (HTTP Origin) of the application call location. An unauthenticated attacker can craft a website that is able to launch SzafirHost application with arbitrary arguments via Szafir SDK Web browser addon. No validation will be performed to check whether the address specified in `document_base_url` parameter is in any way related to the actual address of the calling web application. The URL address specified in `document_base_url` parameter is then shown in the application confirmation prompt. When a victim confirms the execution of the application, it will be called in the context of attacker's website URL and might download additional files and libraries from that website. When victim accepts the application execution for the URL showed in the confirmation prompt with the "remember" option before, the prompt won't be shown and the application will be called in the context of URL provided by the attacker without any interaction. This issue was fixed in version 0.0.17.4.

OpenClaw before 2026.3.31 misclassifies proxied remote requests as loopback connections in the diffs viewer when allowRemoteViewer is disabled, allowing unauthorized access. Attackers can bypass access controls by sending proxied requests that are incorrectly identified as local loopback traffic, circumventing intended remote viewer restrictions.

Use of Less Trusted Source vulnerability in SolidWP Solid Security allows HTTP DoS.This issue affects Solid Security: from n/a through 9.3.1.

9Router is an AI router & token saver. Prior to 0.5.2, 9router determines whether a /v1 LLM proxy request is local by reading the client-controlled Host header, allowing a remote unauthenticated attacker to send Host: localhost and bypass API-key authentication. In the default configuration, this exposes the /v1 proxy to upstream provider calls using stored provider credentials and allows /v1/search with the searxng provider_options.baseUrl parameter to drive server-side requests to internal or cloud-metadata hosts. This issue is fixed in version 0.5.2.

The Unlimited Elements For Elementor (Free Widgets, Addons, Templates) plugin for WordPress is vulnerable to IP Address Spoofing in all versions up to, and including, 1.5.112 due to insufficient IP address validation and/or use of user-supplied HTTP headers as a primary method for IP retrieval. This makes it possible for unauthenticated attackers to bypass antispam functionality in the Form Builder widgets.

The WP Maintenance plugin for WordPress is vulnerable to IP Address Spoofing in all versions up to, and including, 6.1.9.2 due to insufficient IP address validation and use of user-supplied HTTP headers as a primary method for IP retrieval. This makes it possible for unauthenticated attackers to bypass maintenance mode.

HestiaCP versions 1.2.0 through 1.9.4 contain an IP spoofing vulnerability that allows unauthenticated remote attackers to bypass authentication security controls by supplying an arbitrary IP address in the CF-Connecting-IP HTTP header without verifying the request originated from Cloudflare's network. Attackers can exploit this to circumvent fail2ban brute-force protection, bypass per-user IP allowlists, and poison authentication audit logs by spoofing trusted IP addresses on each request.

The IP Vault – WP Firewall plugin for WordPress is vulnerable to IP Address Spoofing in versions up to, and including, 1.1. This is due to insufficient restrictions on where the IP Address information is being retrieved for request logging and login restrictions. Attackers can supply the X-Forwarded-For header with with a different IP Address that will be logged and can be used to bypass settings that may have blocked out an IP address or country from logging in.

ProxySQL is a proxy for MySQL and its forks, as well as PostgreSQL. In versions 2.0.0 through 3.0.8, the ProxySQL MySQL frontend accepts the `PROXY UNKNOWN <addr> <addr> <port> <port>\r\n` PP1 frame as a well-formed PROXY protocol header. The HAProxy PROXY protocol v1 specification says that when the protocol token is `UNKNOWN`, the receiver MUST ignore any address fields that follow it, because the proxy has declared it cannot determine the client identity. ProxySQL parses those address fields anyway via `sscanf` and writes the spoofed source address into the session's `addr.addr` field. From there it flows directly into the query-rule matcher, where the `client_addr` predicate decides routing and ACL. When `mysql-proxy_protocol_networks = '*'` (the default), any TCP peer can send a PP1 frame and choose any source IP claim. With that, any `mysql_query_rules` row pinned to a `client_addr` value is forgeable: the attacker writes the address they want to match into the PP1 line, and ProxySQL routes their query as if it came from that address. In practice this is a routing and ACL bypass. Real deployments use `client_addr` for read-write splitting (internal apps go to the primary, public traffic to read replicas), per-app schema pinning, and query-filter rules (DDL allowed only from admin CIDR, public queries blocked from dangerous patterns). An attacker that can reach the frontend port can forge their way into any of those routes. Version 3.0.9 patches this issue.

The Security, Antivirus, Firewall – S.A.F plugin for WordPress is vulnerable to IP Address Spoofing in versions up to, and including, 2.3.5. This is due to insufficient restrictions on where the IP Address information is being retrieved for request logging and login restrictions. Attackers can supply the X-Forwarded-For header with with a different IP Address that will be logged and can be used to bypass settings that may have blocked out an IP address from logging in.

Cleanuparr is a tool for automating the cleanup of unwanted or blocked files in Sonarr, Radarr, and supported download clients like qBittorrent. Prior to 2.9.10, TrustedNetworkAuthenticationHandler.ResolveClientIp parses the leftmost entry of the X-Forwarded-For header as the client IP. That entry is attacker-controlled — X-Forwarded-For is append-only, so the leftmost value is whatever the original HTTP client claimed. By sending a spoofed local IP in the header, an unauthenticated remote attacker passes the trusted-network check and is logged in as the Cleanuparr administrator. This vulnerability is fixed in 2.9.10.

A security vulnerability has been detected in PbootCMS up to 3.2.12. The affected element is the function get_user_ip of the file core/function/handle.php of the component Header Handler. The manipulation of the argument X-Forwarded-For leads to use of less trusted source. The attack can be initiated remotely. The exploit has been disclosed publicly and may be used.

The Limit Login Attempts Plus plugin for WordPress is vulnerable to IP Address Spoofing in versions up to, and including, 1.1.0. This is due to insufficient restrictions on where the IP Address information is being retrieved for request logging and login restrictions. Attackers can supply the X-Forwarded-For header with with a different IP Address that will be logged and can be used to bypass settings that may have blocked out an IP address or country from logging in.

The AA Block Country plugin for WordPress is vulnerable to IP Address Spoofing in versions up to, and including, 1.0.1. This is due to the plugin trusting user-supplied headers such as HTTP_X_FORWARDED_FOR to determine the client's IP address without proper validation or considering if the server is behind a trusted proxy. This makes it possible for unauthenticated attackers to bypass IP-based access restrictions by spoofing their IP address via the X-Forwarded-For header.

The LOGIN AND REGISTRATION ATTEMPTS LIMIT plugin for WordPress is vulnerable to IP Address Spoofing in versions up to, and including, 2.1. This is due to insufficient restrictions on where the IP Address information is being retrieved for request logging and login restrictions. Attackers can supply the X-Forwarded-For header with with a different IP Address that will be logged and can be used to bypass settings that may have blocked out an IP address from logging in.

Glance through 0.8.5 contains an IP address spoofing vulnerability in the authentication handler that allows unauthenticated attackers to bypass brute-force lockout protections by supplying arbitrary values in the X-Forwarded-For request header when the server proxied option is enabled. Attackers can manipulate the leftmost value of the X-Forwarded-For header to make each login attempt appear to originate from a distinct IP address, preventing the per-IP failed-login counter from reaching the lockout threshold and enabling unlimited credential guessing against the authentication endpoint.

FileCodeBox before 2.4 contains a rate-limit bypass vulnerability in the IPRateLimit class that allows unauthenticated attackers to circumvent request throttling by supplying attacker-controlled X-Real-IP and X-Forwarded-For headers without verification of trusted reverse proxy origin. Attackers can supply unique spoofed IP values on each request to enumerate all possible share codes and retrieve other users' files without authentication.

Eclipse Kura versions prior to 5.6.2 trust the client-supplied X-Forwarded-For HTTP header as the authoritative source of the client IP address in audit log entries. The org.eclipse.kura.web2 (Web Console) and org.eclipse.kura.rest.provider (REST API) components use this header as the primary IP source when initializing audit context, and org.eclipse.kura.jetty.customizer unconditionally installs Jetty's ForwardedRequestCustomizer on all HTTP/HTTPS connectors, causing HttpServletRequest.getRemoteAddr() to reflect the attacker-controlled header value. An unauthenticated remote attacker can exploit this vulnerability to bypass IP-based brute-force protections — such as fail2ban — by spoofing the logged IP address to a non-routable value, allowing a brute-force attack to proceed undetected, or to cause a denial of service against a third party by injecting a victim's IP address and triggering a ban on that address.

LibreTranslate through 1.9.7, fixed in commit 397fd22, contains an IP spoofing vulnerability in the get_remote_address() function that allows unauthenticated attackers to spoof client IP addresses by injecting arbitrary values into the X-Forwarded-For header without trusted proxy validation. Attackers can bypass per-IP rate limiting and flood bans by supplying forged addresses in the X-Forwarded-For header to enable unlimited API abuse.

OfflineIMAP before 8.0.3 trusts the server with their STARTTLS capability prior to authentication, which allows STRIPTLS/man-in-the-middle attacks, taking over the connection and extracting account credentials in cleartext.

Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.25, on AWS Lambda@Edge, CloudFront delivers a request header that appears more than once as several separate entries. The adapter writes each value with Headers.set instead of Headers.append, so every value overwrites the previous one and only the last reaches the application. Repeated request headers such as X-Forwarded-For, Forwarded, and Via are silently truncated to a single value. Request middleware sees only the last value of a repeated header instead of the full chain. For applications that base access control on the X-Forwarded-For chain, this can weaken or alter that decision; for auditing, hop history is lost. This vulnerability is fixed in 4.12.25.

WWBN AVideo is an open source video platform. In versions up to and including 26.0, the `getRealIpAddr()` function in `objects/functions.php` trusts user-controlled HTTP headers to determine the client's IP address. An attacker can spoof their IP address by sending forged headers, bypassing any IP-based access controls or audit logging. Commit 1a1df6a9377e5cc67d1d0ac8ef571f7abbffbc6c contains a patch.

Movable Type contains an issue with use of less trusted source. If exploited, tampered email to reset a password may be sent by a remote unauthenticated attacker.

Passbolt API before 5, if the server is misconfigured (with an incorrect installation process and disregarding of Health Check results), can send email messages with a domain name taken from an attacker-controlled HTTP Host header.

An issue was discovered in the oidc (aka OpenID Connect Authentication) extension before 4.0.0 for TYPO3. The account linking logic allows a pre-hijacking attack, leading to Account Takeover. The attack can only be exploited if the following requirements are met: (1) an attacker can anticipate the e-mail address of the user, (2) an attacker can register a public frontend user account using that e-mail address before the user's first OIDC login, and (3) the IDP returns an email field containing the e-mail address of the user,

In sshd in OpenSSH before 10.4, DisableForwarding=yes was supposed to take precedence over PermitTunnel=yes, but did not.

The Caddy Defender plugin is a middleware for Caddy that allows users to block or manipulate requests based on the client's IP address. Prior to version 0.10.1, Caddy Defender used `r.RemoteAddr` when evaluating whether a request should be blocked. `RemoteAddr` is the address of the immediate peer connected to Caddy. In deployments where Caddy is behind a trusted proxy, CDN, or load balancer, the immediate peer is usually the proxy, not the original client. Caddy resolves the original client address into its `client_ip` request variable after applying the configured `trusted_proxies` policy, but Defender did not use that value. As a result, clients from blocked IP ranges could bypass Defender when accessing Caddy through a trusted proxy whose own IP address was not blocked. This affects deployments that use Defender behind trusted proxies and expect it to enforce blocking based on the real client IP. The issue is fixed in version 0.10.1 by making Defender prefer Caddys resolved `client_ip` request variable when it is available. Defender falls back to `RemoteAddr` only when Caddy has not provided a resolved client IP. There is no complete workaround in affected Defender versions for deployments that rely on Caddy's trusted proxy client IP resolution. Until upgrading, affected users should enforce equivalent IP blocking at the trusted proxy, CDN, load balancer, firewall, or other edge layer before traffic reaches Caddy. Deployments where Caddy receives traffic directly from clients, without an intermediate trusted proxy, are not affected by this bypass.

Raytha CMS allows an attacker to spoof `X-Forwarded-Host` or `Host` headers to attacker controlled domain. The attacker (who knows the victim's email address) can force the server to send an email with password reset link pointing to the domain from spoofed header. When victim clicks the link, browser sends request to the attacker’s domain with the token in the path allowing the attacker to capture the token. This allows the attacker to reset victim's password and take over the victim's account. This issue was fixed in version 1.4.6.

wpDiscuz before 7.6.47 contains an IP spoofing vulnerability in the getIP() function that allows attackers to bypass IP-based rate limiting and ban enforcement by trusting untrusted HTTP headers. Attackers can set HTTP_CLIENT_IP or HTTP_X_FORWARDED_FOR headers to spoof their IP address and circumvent security controls.

The optional feature 'Anti-Virus & Sandbox' of i-FILTER contains an issue with improper pattern file validation. If exploited, the product may treat an unauthorized pattern file as an authorized. If the product uses a specially crafted pattern file, information in the server where the product is running may be retrieved, and/or cause a denial of service (DoS) condition.

Bypass Connection Restriction vulnerability in Hitachi Infrastructure Analytics Advisor (Data Center Analytics component), Hitachi Ops Center Analyzer  (Hitachi Ops Center Analyzer detail view component).This issue affects Hitachi Infrastructure Analytics Advisor:; Hitachi Ops Center Analyzer: from 10.0.0-00 before 11.0.4-00.

PVWA (Password Vault Web Access) in CyberArk Privileged Access Manager Self-Hosted before 14.4 does not properly address environment issues that can contribute to Host header injection.

An issue was discovered in Canonical ADSys upstream versions through v0.16.2. During Active Directory Certificate Services (AD CS) certificate auto-enrollment via the vendored Samba client script (internal/policies/certificate/python/vendor_samba/gp/gp_cert_auto_enroll_ext.py), ADSys utilizes a plaintext HTTP connection (http://) instead of a secure HTTPS connection (https://) to request the CA certificate from the Active Directory Certificate Services server (GetCACert). An unauthenticated network attacker positioned between the managed Ubuntu host and the configured AD CS CA hostname can conduct a Man-in-the-Middle (MITM) attack. By intercepting the plaintext HTTP request, the attacker can supply an arbitrary, attacker-controlled Root CA certificate. Because the system automatically accepts this certificate and registers it into the local system trust store via update-ca-certificates, this results in system-wide trust store poisoning. Consequently, TLS clients utilizing the operating system trust store on the affected machine will accept rogue certificates for arbitrary domains, enabling persistent decryption and interception of subsequent TLS connections. This issue is resolved in version v0.16.3.

Bulwark Webmail is a self-hosted webmail client for Stalwart Mail Server. Prior to 1.4.11, the getClientIP() function in lib/admin/session.ts trusted the first (leftmost) entry of the X-Forwarded-For header, which is fully controlled by the client. An attacker could forge their source IP address to bypass IP-based rate limiting (enabling brute-force attacks against the admin login) or forge audit log entries (making malicious activity appear to originate from arbitrary IP addresses). This vulnerability is fixed in 1.4.11.

Hono is a Web application framework that provides support for any JavaScript runtime. From 4.3.3 before 4.12.27, the AWS API Gateway v1 adapter can drop a distinct repeated request header value because it de-duplicates values using a substring comparison instead of an exact match, so middleware or application logic that depends on the complete X-Forwarded-For chain, rate limiting, audit logging, or proxy-chain validation can receive incomplete data. This issue is fixed in version 4.12.27.

Meshtastic is an open source mesh networking solution. In the current Meshtastic architecture, a Node is identified by their NodeID, generated from the MAC address, rather than their public key. This aspect downgrades the security, specifically by abusing the HAM mode which doesn't use encryption. An attacker can, as such, forge a NodeInfo on behalf of a victim node advertising that the HAM mode is enabled. This, in turn, will allow the other nodes on the mesh to accept the new information and overwriting the NodeDB. The other nodes will then only be able to send direct messages to the victim by using the shared channel key instead of the PKC. Additionally, because HAM mode by design doesn't provide any confidentiality or authentication of information, the attacker could potentially also be able to change the Node details, like the full name, short code, etc. To keep the attack persistent, it is enough to regularly resend the forged NodeInfo, in particular right after the victim sends their own. A patch is available in version 2.7.6.834c3c5.

Retool (self-hosted) before 3.196.0 allows Host header injection. When the BASE_DOMAIN environment variable is not set, the HTTP host header can be manipulated.

Summary When trustProxy is configured with a restrictive trust function (e.g., a specific IP like trustProxy: '10.0.0.1', a subnet, a hop count, or a custom function), the request.protocol and request.host getters read X-Forwarded-Proto and X-Forwarded-Host headers from any connection — including connections from untrusted IPs. This allows an attacker connecting directly to Fastify (bypassing the proxy) to spoof both the protocol and host seen by the application. Affected Versions fastify <= 5.8.2 Impact Applications using request.protocol or request.host for security decisions (HTTPS enforcement, secure cookie flags, CSRF origin checks, URL construction, host-based routing) are affected when trustProxy is configured with a restrictive trust function. When trustProxy: true (trust everything), both host and protocol trust all forwarded headers — this is expected behavior. The vulnerability only manifests with restrictive trust configurations.

In NLnet Labs Unbound 1.6.2 up to and including 1.25.1, when Unbound is configured with the 'respip' module in front of the validator together with a 'response-ip' redirect rule or an RPZ file with an RPZ-IP trigger, the rewriting handler does not check the security status of the upstream answer and can instead rewrite a BOGUS A/AAAA answer to point to an operator's configured IP. If the validator finds an expired or otherwise invalid RRSIG on an answer whose A record falls within a 'response-ip'/RPZ configuration, the answer is still rewritten and given a hard coded security level of INSECURE. This results in the client receiving an INSECURE NOERROR reply rewritten by the operator's configured IP. A malicious actor can exploit the possible poisonous effect by spoofing a BOGUS A/AAAA answer that falls inside the operator's configured subnet rewrites. Such DNSSEC protected answers are then insecurely redirected to the operator's configured target.

Dell PowerProtect Data Domain, versions 7.7.1.0 through 8.7, LTS2026 release version 8.6.1.0 through 8.6.1.10, LTS2025 release version 8.3.1.0 through 8.3.1.30, LTS2024 release versions 7.13.1.0 through 7.13.1.70 contain an use of less trusted source vulnerability. A high privileged attacker with remote access could potentially exploit this vulnerability, leading to information tampering.

In Bun before 1.3.5, the default trusted dependencies list (aka trust allow list) can be spoofed by a non-npm package in the case of a matching name (for file, link, git, or github).

RICOH Streamline NX versions 3.5.1 to 24R3 are vulnerable to tampering with operation history. If an attacker can perform a man-in-the-middle attack, they may alter the values of HTTP requests, which could result in tampering with the operation history of the product’s management tool.

RICOH Streamline NX V3 PC Client versions 3.5.0 to 3.7.0 contains an issue with use of less trusted source, which may allow an attacker who can conduct a man-in-the-middle attack to eavesdrop upgrade requests and execute a malicious DLL with custom code.

Shynet before 0.14.0 allows Host header injection in the password reset flow.

In the KDE Connect information-exchange protocol before 2025-04-18, a packet can be crafted to temporarily change the displayed information about a device, because broadcast UDP is used. This affects KDE Connect before 1.33.0 on Android, KDE Connect before 25.04 on desktop, KDE Connect before 0.5 on iOS, Valent before 1.0.0.alpha.47, and GSConnect before 59.

SSL.com before 2025-04-19, when domain validation method 3.2.2.4.14 is used, processes certificate requests such that a trusted TLS certificate may be issued for the domain name of a requester's email address, even when the requester does not otherwise establish administrative control of that domain.

In nspawn in systemd 233 through 259 before 260, an escape-to-host action can occur via a crafted optional config file.

### Summary `AllowedHostsMiddleware` trusts the `X-Forwarded-Host` header as a fallback when the `Host` header is absent. Since `X-Forwarded-Host` is a client-controllable header, an attacker can bypass the allowed hosts validation by omitting the `Host` header and supplying an `X-Forwarded-Host` header set to a whitelisted domain. This enables host header injection attacks such as password reset poisoning, cache poisoning, and server-side request routing manipulation. ### Details In `AllowedHostsMiddleware.__call__`, the host value used for validation is resolved as follows: https://github.com/litestar-org/litestar/blob/main/litestar/middleware/allowed_hosts.py#L68 ```python headers = MutableScopeHeaders(scope=scope) if host := headers.get("host", headers.get("x-forwarded-host", "")).split(":")[0]: if self.allowed_hosts_regex.fullmatch(host): await self.app(scope, receive, send) return ``` When `Host` is absent (e.g., HTTP/1.0 clients, misconfigured proxies, or raw TCP connections), the middleware falls back to `X-Forwarded-Host` without any verification that the request actually passed through a trusted reverse proxy. An attacker can send a request with no `Host` header and set `X-Forwarded-Host` to any whitelisted domain, bypassing the entire allowed hosts check. The application then processes the request as if it originated from a trusted host. This is particularly dangerous when applications use the resolved host value for: - Generating password reset links (`Host` header injection → link points to attacker domain) - Cache key generation (cache poisoning) - Routing or backend selection decisions ### PoC ```python """ PoC: Allowed Hosts Bypass via X-Forwarded-Host in Litestar 3.0.0b0 Affected: litestar/middleware/allowed_hosts.py:68 -> headers.get("host", headers.get("x-forwarded-host", "")).split(":")[0] """ import asyncio from litestar import Litestar, get from litestar.config.allowed_hosts import AllowedHostsConfig from litestar.testing import TestClient @get("/") async def index() -> dict: return {"status": "ok"} app = Litestar( route_handlers=[index], allowed_hosts=AllowedHostsConfig(allowed_hosts=["trusted.example.com"]), ) # --- 1. Baseline: invalid host is blocked --- with TestClient(app=app) as c: resp = c.get("/", headers={"host": "evil.com"}) assert resp.status_code == 400 print(f"[*] Host: evil.com -> {resp.status_code} (blocked)") # --- 2. Bypass: ASGI scope without Host, with X-Forwarded-Host --- async def test_bypass(): scope = { "type": "http", "method": "GET", "path": "/", "root_path": "", "scheme": "http", "query_string": b"", "headers": [ # No "host" header — only x-forwarded-host (b"x-forwarded-host", b"trusted.example.com"), ], "server": ("testserver", 80), "app": app, "litestar_app": app, "state": {}, } captured = {} async def receive(): return {"type": "http.request", "body": b""} async def send(message): if message["type"] == "http.response.start": captured["status"] = message["status"] await app(scope, receive, send) return captured["status"] status = asyncio.run(test_bypass()) print(f"[*] No Host + X-Forwarded-Host: trusted.example.com -> {status} (bypassed)") assert status == 200, f"Expected 200, got {status}" print(f"[!] AllowedHosts check passed using client-controlled X-Forwarded-Host") ``` **Output:** ``` [*] Host: evil.com -> 400 (blocked) [*] No Host + X-Forwarded-Host: trusted.example.com -> 200 (bypassed) [!] AllowedHosts check passed using client-controlled X-Forwarded-Host ``` ### Impact This is a host validation bypass vulnerability. Any application using `AllowedHostsConfig` is affected when deployed without a reverse proxy that strips `X-Forwarded-Host`, or when accepting HTTP/1.0 connections. An attacker can bypass the allowed hosts restriction and have requests processed as if they originated from a trusted host. This can lead to: - **Password reset poisoning**: if the application uses the host value to generate reset links, the attacker can redirect them to a malicious domain - **Cache poisoning**: cached responses keyed on the host value can be polluted with attacker-controlled content - **Routing manipulation**: backend routing decisions based on host value can be influenced