CWE-636

Remote Registry Service Elevation of Privilege Vulnerability

Moby is an open source container framework developed by Docker Inc. that is distributed as Docker, Mirantis Container Runtime, and various other downstream projects/products. The Moby daemon component (`dockerd`), which is developed as moby/moby, is commonly referred to as *Docker*. Swarm Mode, which is compiled in and delivered by default in dockerd and is thus present in most major Moby downstreams, is a simple, built-in container orchestrator that is implemented through a combination of SwarmKit and supporting network code. The overlay network driver is a core feature of Swarm Mode, providing isolated virtual LANs that allow communication between containers and services across the cluster. This driver is an implementation/user of VXLAN, which encapsulates link-layer (Ethernet) frames in UDP datagrams that tag the frame with a VXLAN Network ID (VNI) that identifies the originating overlay network. In addition, the overlay network driver supports an optional, off-by-default encrypted mode, which is especially useful when VXLAN packets traverses an untrusted network between nodes. Encrypted overlay networks function by encapsulating the VXLAN datagrams through the use of the IPsec Encapsulating Security Payload protocol in Transport mode. By deploying IPSec encapsulation, encrypted overlay networks gain the additional properties of source authentication through cryptographic proof, data integrity through check-summing, and confidentiality through encryption. When setting an endpoint up on an encrypted overlay network, Moby installs three iptables (Linux kernel firewall) rules that enforce both incoming and outgoing IPSec. These rules rely on the u32 iptables extension provided by the xt_u32 kernel module to directly filter on a VXLAN packet's VNI field, so that IPSec guarantees can be enforced on encrypted overlay networks without interfering with other overlay networks or other users of VXLAN. Two iptables rules serve to filter incoming VXLAN datagrams with a VNI that corresponds to an encrypted network and discards unencrypted datagrams. The rules are appended to the end of the INPUT filter chain, following any rules that have been previously set by the system administrator. Administrator-set rules take precedence over the rules Moby sets to discard unencrypted VXLAN datagrams, which can potentially admit unencrypted datagrams that should have been discarded. The injection of arbitrary Ethernet frames can enable a Denial of Service attack. A sophisticated attacker may be able to establish a UDP or TCP connection by way of the container’s outbound gateway that would otherwise be blocked by a stateful firewall, or carry out other escalations beyond simple injection by smuggling packets into the overlay network. Patches are available in Moby releases 23.0.3 and 20.10.24. As Mirantis Container Runtime's 20.10 releases are numbered differently, users of that platform should update to 20.10.16. Some workarounds are available. Close the VXLAN port (by default, UDP port 4789) to incoming traffic at the Internet boundary to prevent all VXLAN packet injection, and/or ensure that the `xt_u32` kernel module is available on all nodes of the Swarm cluster.

A vulnerability in an API endpoint of Cisco Application Policy Infrastructure Controller (APIC) and Cisco Cloud Application Policy Infrastructure Controller (Cloud APIC) could allow an authenticated, remote attacker to elevate privileges to Administrator on an affected device. This vulnerability is due to an improper policy default setting. An attacker could exploit this vulnerability by using a non-privileged credential for Cisco ACI Multi-Site Orchestrator (MSO) to send a specific API request to a managed Cisco APIC or Cloud APIC device. A successful exploit could allow the attacker to obtain Administrator credentials on the affected device.

Moby) is an open source container framework developed by Docker Inc. that is distributed as Docker, Mirantis Container Runtime, and various other downstream projects/products. The Moby daemon component (`dockerd`), which is developed as moby/moby is commonly referred to as *Docker*. Swarm Mode, which is compiled in and delivered by default in `dockerd` and is thus present in most major Moby downstreams, is a simple, built-in container orchestrator that is implemented through a combination of SwarmKit and supporting network code. The `overlay` network driver is a core feature of Swarm Mode, providing isolated virtual LANs that allow communication between containers and services across the cluster. This driver is an implementation/user of VXLAN, which encapsulates link-layer (Ethernet) frames in UDP datagrams that tag the frame with the VXLAN metadata, including a VXLAN Network ID (VNI) that identifies the originating overlay network. In addition, the overlay network driver supports an optional, off-by-default encrypted mode, which is especially useful when VXLAN packets traverses an untrusted network between nodes. Encrypted overlay networks function by encapsulating the VXLAN datagrams through the use of the IPsec Encapsulating Security Payload protocol in Transport mode. By deploying IPSec encapsulation, encrypted overlay networks gain the additional properties of source authentication through cryptographic proof, data integrity through check-summing, and confidentiality through encryption. When setting an endpoint up on an encrypted overlay network, Moby installs three iptables (Linux kernel firewall) rules that enforce both incoming and outgoing IPSec. These rules rely on the `u32` iptables extension provided by the `xt_u32` kernel module to directly filter on a VXLAN packet's VNI field, so that IPSec guarantees can be enforced on encrypted overlay networks without interfering with other overlay networks or other users of VXLAN. The `overlay` driver dynamically and lazily defines the kernel configuration for the VXLAN network on each node as containers are attached and detached. Routes and encryption parameters are only defined for destination nodes that participate in the network. The iptables rules that prevent encrypted overlay networks from accepting unencrypted packets are not created until a peer is available with which to communicate. Encrypted overlay networks silently accept cleartext VXLAN datagrams that are tagged with the VNI of an encrypted overlay network. As a result, it is possible to inject arbitrary Ethernet frames into the encrypted overlay network by encapsulating them in VXLAN datagrams. The implications of this can be quite dire, and GHSA-vwm3-crmr-xfxw should be referenced for a deeper exploration. Patches are available in Moby releases 23.0.3, and 20.10.24. As Mirantis Container Runtime's 20.10 releases are numbered differently, users of that platform should update to 20.10.16. Some workarounds are available. In multi-node clusters, deploy a global ‘pause’ container for each encrypted overlay network, on every node. For a single-node cluster, do not use overlay networks of any sort. Bridge networks provide the same connectivity on a single node and have no multi-node features. The Swarm ingress feature is implemented using an overlay network, but can be disabled by publishing ports in `host` mode instead of `ingress` mode (allowing the use of an external load balancer), and removing the `ingress` network. If encrypted overlay networks are in exclusive use, block UDP port 4789 from traffic that has not been validated by IPSec.

Windows BitLocker Information Disclosure Vulnerability

The Frontend Admin by DynamiApps plugin for WordPress is vulnerable to improper missing encryption exception handling on the 'fea_encrypt' function in all versions up to, and including, 3.19.4. This makes it possible for unauthenticated attackers to manipulate the user processing forms, which can be used to add and edit administrator user for privilege escalation, or to automatically log in users for authentication bypass, or manipulate the post processing form that can be used to inject arbitrary web scripts. This can only be exploited if the 'openssl' php extension is not loaded on the server.

Moby is an open source container framework developed by Docker Inc. that is distributed as Docker, Mirantis Container Runtime, and various other downstream projects/products. The Moby daemon component (`dockerd`), which is developed as moby/moby is commonly referred to as *Docker*. Swarm Mode, which is compiled in and delivered by default in `dockerd` and is thus present in most major Moby downstreams, is a simple, built-in container orchestrator that is implemented through a combination of SwarmKit and supporting network code. The `overlay` network driver is a core feature of Swarm Mode, providing isolated virtual LANs that allow communication between containers and services across the cluster. This driver is an implementation/user of VXLAN, which encapsulates link-layer (Ethernet) frames in UDP datagrams that tag the frame with the VXLAN metadata, including a VXLAN Network ID (VNI) that identifies the originating overlay network. In addition, the overlay network driver supports an optional, off-by-default encrypted mode, which is especially useful when VXLAN packets traverses an untrusted network between nodes. Encrypted overlay networks function by encapsulating the VXLAN datagrams through the use of the IPsec Encapsulating Security Payload protocol in Transport mode. By deploying IPSec encapsulation, encrypted overlay networks gain the additional properties of source authentication through cryptographic proof, data integrity through check-summing, and confidentiality through encryption. When setting an endpoint up on an encrypted overlay network, Moby installs three iptables (Linux kernel firewall) rules that enforce both incoming and outgoing IPSec. These rules rely on the `u32` iptables extension provided by the `xt_u32` kernel module to directly filter on a VXLAN packet's VNI field, so that IPSec guarantees can be enforced on encrypted overlay networks without interfering with other overlay networks or other users of VXLAN. An iptables rule designates outgoing VXLAN datagrams with a VNI that corresponds to an encrypted overlay network for IPsec encapsulation. Encrypted overlay networks on affected platforms silently transmit unencrypted data. As a result, `overlay` networks may appear to be functional, passing traffic as expected, but without any of the expected confidentiality or data integrity guarantees. It is possible for an attacker sitting in a trusted position on the network to read all of the application traffic that is moving across the overlay network, resulting in unexpected secrets or user data disclosure. Thus, because many database protocols, internal APIs, etc. are not protected by a second layer of encryption, a user may use Swarm encrypted overlay networks to provide confidentiality, which due to this vulnerability this is no longer guaranteed. Patches are available in Moby releases 23.0.3, and 20.10.24. As Mirantis Container Runtime's 20.10 releases are numbered differently, users of that platform should update to 20.10.16. Some workarounds are available. Close the VXLAN port (by default, UDP port 4789) to outgoing traffic at the Internet boundary in order to prevent unintentionally leaking unencrypted traffic over the Internet, and/or ensure that the `xt_u32` kernel module is available on all nodes of the Swarm cluster.

Snuffleupagus is a module that raises the cost of attacks against website by killing bug classes and providing a virtual patching system. On deployments of Snuffleupagus prior to version 0.13.0 with the non-default upload validation feature enabled and configured to use one of the upstream validation scripts based on Vulcan Logic Disassembler (VLD) while the VLD extension is not available to the CLI SAPI, all files from multipart POST requests are evaluated as PHP code. The issue was fixed in version 0.13.0.

OpenViking prior to version 0.3.9 contains an authentication bypass vulnerability in the VikingBot OpenAPI HTTP route surface where the authentication check fails open when the api_key configuration value is unset or empty. Remote attackers with network access to the exposed service can invoke privileged bot-control functionality without providing a valid X-API-Key header, including submitting attacker-controlled prompts, creating or using bot sessions, and accessing downstream tools, integrations, secrets, or data accessible to the bot.

free5GC is an open-source implementation of the 5G core network. In versions 4.2.1 and below of the UDR service, the handler for reading Traffic Influence Subscriptions checks whether the influenceId path segment equals subs-to-notify, but does not return after sending the HTTP 404 response when validation fails. Execution continues and the subscription data is returned alongside the 404 response. An unauthenticated attacker with access to the 5G Service Based Interface can read arbitrary Traffic Influence Subscriptions, including SUPIs/IMSIs, DNNs, S-NSSAIs, and callback URIs, by supplying any value for the influenceId path segment. A patched version was not available at the time of publication.

Vault Community and Vault Enterprise (“Vault”) clusters using Vault’s Integrated Storage backend are vulnerable to a denial-of-service (DoS) attack through memory exhaustion through a Raft cluster join API endpoint . An attacker may send a large volume of requests to the endpoint which may cause Vault to consume excessive system memory resources, potentially leading to a crash of the underlying system and the Vault process itself. This vulnerability, CVE-2024-8185, is fixed in Vault Community 1.18.1 and Vault Enterprise 1.18.1, 1.17.8, and 1.16.12.

free5GC is an open-source implementation of the 5G core network. In versions 4.2.1 and below of the UDR service, the handler for creating or updating Traffic Influence Subscriptions checks whether the influenceId path segment equals subs-to-notify, but does not return after sending the HTTP 404 response when validation fails. Execution continues and the subscription is created or overwritten regardless. An unauthenticated attacker with access to the 5G Service Based Interface can create or overwrite arbitrary Traffic Influence Subscriptions, including injecting attacker-controlled notificationUri values and arbitrary SUPIs, by supplying any value for the influenceId path segment. A patched version was not available at the time of publication.

Net::IMAP implements Internet Message Access Protocol (IMAP) client functionality in Ruby. Prior to versions 0.3.10, 0.4.24, 0.5.14, and 0.6.4, a man-in-the-middle attacker can cause Net::IMAP#starttls to return "successfully", without starting TLS. This issue has been patched in versions 0.3.10, 0.4.24, 0.5.14, and 0.6.4.

OpenClaw before 2026.3.31 contains a decompression bomb vulnerability in image processing that fails to properly enforce pixel-limit guards on sips. Attackers can exploit this by uploading oversized images to cause denial of service through excessive memory consumption.

free5GC is an open-source implementation of the 5G core network. In versions 4.2.1 and below of the UDR service, the PUT handler for updating Policy Data notification subscriptions at /nudr-dr/v2/policy-data/subs-to-notify/{subsId} does not return after request body retrieval or deserialization errors. Although HTTP 500 or 400 error responses are sent, execution continues and the processor is invoked with a potentially uninitialized or partially initialized PolicyDataSubscription object. This fail-open behavior may allow unintended modification of existing Policy Data notification subscriptions with invalid or empty input, depending on downstream processor and storage behavior. A patched version was not available at the time of publication.

OpenClaw before 2026.4.8 contains an approval-timeout fallback mechanism that bypasses strictInlineEval explicit-approval requirements on gateway and node exec hosts. Attackers can exploit this timeout fallback to execute inline eval commands that should require explicit user approval, circumventing the intended security boundary.

An administrator may attempt to block all traffic by configuring a pass filter with an empty table. However, in UBR, an empty list does not enforce any restrictions and allows all network traffic to pass unfiltered.

An administrator may attempt to block all networks by specifying "\*" or "all" as the network identifier. However, these values are not supported and do not trigger any validation error. Instead, they are silently interpreted as network 0 which results in no networks being blocked at all.

In Splunk Add-on Builder (AoB) versions below 4.1.2 and the Splunk CloudConnect SDK versions below 3.1.3, requests to third-party APIs through the REST API Modular Input incorrectly revert to using HTTP to connect after a failure to connect over HTTPS occurs.

Vault and Vault Enterprise TLS certificates auth method did not correctly validate OCSP responses when one or more OCSP sources were configured. This vulnerability, CVE-2024-2660, affects Vault and Vault Enterprise 1.14.0 and above, and is fixed in Vault 1.16.0 and Vault Enterprise 1.16.1, 1.15.7, and 1.14.11.

pyOpenSSL is a Python wrapper around the OpenSSL library. Starting in version 0.14.0 and prior to version 26.0.0, if a user provided callback to `set_tlsext_servername_callback` raised an unhandled exception, this would result in a connection being accepted. If a user was relying on this callback for any security-sensitive behavior, this could allow bypassing it. Starting in version 26.0.0, unhandled exceptions now result in rejecting the connection.

A vulnerability was reported on some Lenovo Notebook systems that could allow an attacker with physical access to elevate privileges under certain conditions during a BIOS update performed by Lenovo Vantage.

OpenClaw before 2026.3.31 contains a fail-open vulnerability in the plugin installation flow where security scan failures do not block installation. Attackers can exploit scan failures to install untrusted plugins when operators proceed despite visible scan warnings.

The MCP Registry provides MCP clients with a list of MCP servers, like an app store for MCP servers. Prior to 1.7.9, OCI ownership validation skips label-match check when upstream OCI registry returns HTTP 429, letting any authenticated publisher bind their io.github.<user>/* namespace to OCI images they do not control. internal/validators/registries/oci.go:104-119 fails open on http.StatusTooManyRequests: when the registry's anonymous fetch to the upstream OCI registry is rate-limited, ValidateOCI returns nil and the publish is accepted without ever running the io.modelcontextprotocol.server.name label-match check at lines 122-141. That label check is the only cross-system ownership proof the registry applies to OCI packages — every other registry type (NPM, PyPI, NuGet, MCPB) treats a non-200 upstream response as a hard error. This vulnerability is fixed in 1.7.9.

OpenClaw before 2026.5.6 contains an improper access control vulnerability in Mattermost event handlers that fails to validate channel type metadata. Attackers can bypass intended DM policy decisions by sending crafted Mattermost events missing channel type information to process restricted content.

Helm is a package manager for Charts for Kubernetes. From 4.0.0 to 4.1.3, Helm will install plugins missing provenance (.prov file) when signature verification is required. This vulnerability is fixed in 4.1.4.

VTun-ng is a Virtual Tunnel over TCP/IP network. In versions 3.0.17 and below, failure to initialize encryption modules might cause reversion to plaintext due to insufficient error handling. The bug was first introduced in VTun-ng version 3.0.12. This is fixed in version 3.0.18. To workaround this issue, avoid blowfish-256.

A vulnerability was reported in BIOS for ThinkPad P14s Gen 2, P15s Gen 2, T14 Gen 2, and T15 Gen 2 that could cause the system to recover to insecure settings if the BIOS becomes corrupt.

OpenClaw before 2026.4.25 contains a scope containment bypass vulnerability in device re-pairing that allows authenticated operators to restore broader scopes than intended by submitting empty-scope re-pairing requests. Attackers can exploit this by sending re-pairing requests with empty scope sets to skip containment guards and retain unauthorized device access.

fast-jwt provides fast JSON Web Token (JWT) implementation. In 6.1.0 and earlier, fast-jwt does not validate the crit (Critical) Header Parameter defined in RFC 7515 §4.1.11. When a JWS token contains a crit array listing extensions that fast-jwt does not understand, the library accepts the token instead of rejecting it. This violates the MUST requirement in the RFC.

Incorrect behavior order in the Infotainment / Digital Round display of the Indian Motorcycle Scout Bobber + Tech 2025 model year allows an adjacent-network attacker to bypass the PIN entry screen. The Infotainment uses presence of Wireless Control Module (WCM) traffic during its boot window as a proxy for whether an immobilizer is fitted; if no WCM messages are observed, it skips the PIN entry screen and shows the normal user interface. An attacker who silences the WCM during the boot window — for example via a separately tracked CAN bus-off technique — can present a fully unlocked Infotainment despite the PIN never being entered. Specific timing and protocol details have been withheld pending vendor remediation.

Incorrect behavior order in the Infotainment / Digital Round display of the Indian Motorcycle Scout Bobber + Tech 2025 model year allows an adjacent-network attacker to bypass the PIN entry screen. The Infotainment uses presence of Wireless Control Module (WCM) traffic during its boot window as a proxy for whether an immobilizer is fitted; if no WCM messages are observed, it skips the PIN entry screen and shows the normal user interface. An attacker who silences the WCM during the boot window — for example via a separately tracked CAN bus-off technique — can present a fully unlocked Infotainment despite the PIN never being entered. Specific timing and protocol details have been withheld pending vendor remediation.

OpenClaw before 2026.3.11 contains a credential fallback vulnerability where unavailable local gateway.auth.token and gateway.auth.password SecretRefs are treated as unset, allowing fallback to remote credentials in local mode. Attackers can exploit misconfigured local auth references to cause CLI and helper paths to select incorrect credential sources, potentially bypassing intended local authentication boundaries.

## Summary There is a medium severity vulnerability in Traefik's Kubernetes Ingress NGINX provider that causes affected routes to fail open. When an Ingress explicitly enables BasicAuth or DigestAuth through the supported `nginx.ingress.kubernetes.io/auth-type` and `auth-secret` annotations, but the referenced auth Secret cannot be resolved or parsed, Traefik logs the resolution error, skips installing the authentication middleware, and still emits a router to the backend service. A route that operators intended to protect is therefore published to the data plane without its authentication control, allowing unauthenticated access to the backend. The trigger is an invalid or unresolved auth dependency — a missing, malformed, unreadable, or policy-denied Secret — rather than an intentionally unprotected route. ## Patches - https://github.com/traefik/traefik/releases/tag/v3.7.5 ## For more information If you have any questions or comments about this advisory, please [open an issue](https://github.com/traefik/traefik/issues). <details> <summary>Original Description</summary> ### Summary Traefik's Kubernetes Ingress NGINX provider can fail open for routes that explicitly configure BasicAuth or DigestAuth through supported ingress-nginx annotations. When an Ingress contains `nginx.ingress.kubernetes.io/auth-type: basic` or `digest`, but the referenced `nginx.ingress.kubernetes.io/auth-secret` cannot be resolved or parsed, Traefik logs the auth resolution error, skips installing the BasicAuth/DigestAuth middleware, and still emits a router to the backend service. This can expose a route that operators intended to protect. The issue is not that an invalid Secret exists; the issue is that an explicitly auth-protected Ingress location is translated into a live backend route where the authentication control is removed from the generated data-plane configuration, with only a controller log entry, instead of failing closed. Tested affected versions: - Current `master`: `29406d42898547f1ffabd904f66af06c212740cf` - Latest tag tested by me: `v3.7.1` / `fa49e2bcad7ffd8a80accdf1fae1ae480913d93d` The KubernetesIngressNGINX provider is documented as no longer experimental as of v3.6.2, and the `auth-type`, `auth-secret`, `auth-secret-type`, and `auth-realm` annotations are documented supported annotations. ### Details The root cause is in `pkg/provider/kubernetes/ingress-nginx/build.go`. During provider translation, auth is pre-resolved for each location: ```go if ing.config.AuthType != nil { basic, digest, err := p.resolveBasicAuth(ing.Namespace, ing.config) if err != nil { logger.Error(). Err(err). Str("ingress", fmt.Sprintf("%s/%s rule-%d path-%d", ing.Namespace, ing.Name, ri, pi)). Msg("Cannot resolve auth secret, skipping auth middleware") } else { loc.BasicAuth = basic loc.DigestAuth = digest } } ``` The error is logged, but `loc.Error` is not set. Later, `pkg/provider/kubernetes/ingress-nginx/translator.go` only routes to `unavailable-service` when `loc.Error` is true. Since this auth error leaves `loc.Error` false, the generated router continues to use the real backend service, and `applyMiddlewares` has no BasicAuth/DigestAuth middleware to attach. This differs from nearby fail-closed behavior for comparable provider translation failures: - `auth-tls-secret` resolution failure skips the affected ingress. - `custom-headers` ConfigMap resolution failure sets `loc.Error = true`, causing the translator to avoid normal backend exposure. Security invariant: > If an Ingress location explicitly configures BasicAuth/DigestAuth, Traefik should not forward that location to the backend unless the corresponding auth middleware is installed. Reasonable fail-closed behaviors would include omitting the router, routing it to `unavailable-service`, returning 503, or attaching a deny-all middleware until the auth dependency is valid. ### Expected behavior An Ingress location with explicit `auth-type: basic` or `auth-type: digest` must not forward requests to the backend unless the generated Traefik router has the corresponding BasicAuth/DigestAuth middleware attached. If the referenced auth Secret is missing, malformed, unreadable, denied by namespace policy, or otherwise unusable, Traefik should fail closed for that location. ### Actual behavior When `auth-secret` resolution fails, Traefik still creates a router to the backend service and only omits the BasicAuth/DigestAuth middleware. The only indication is a controller log entry: ```text Cannot resolve auth secret, skipping auth middleware ``` ### PoC I reproduced this with a clean fake Kubernetes provider state. The reproduction does not use Docker provider labels, dashboard/API routing, lab backends, or public network targets. Minimal Kubernetes objects: - `IngressClass` named `nginx` with controller `k8s.io/ingress-nginx` - `Service` named `whoami` in namespace `default` - `EndpointSlice` for the `whoami` service - `Ingress` with `ingressClassName: nginx`, a backend pointing to `whoami`, and these annotations: ```yaml nginx.ingress.kubernetes.io/auth-type: "basic" nginx.ingress.kubernetes.io/auth-secret-type: "auth-file" nginx.ingress.kubernetes.io/auth-secret: "default/missing-basic-auth" ``` The referenced Secret intentionally does not exist. The expected secure behavior is fail-closed for this auth-configured route. The observed behavior is a normal router to the backend without BasicAuth/DigestAuth. Key failing assertion from the regression harness: ```text router forwards to backend service without BasicAuth/DigestAuth when auth-secret is missing; middlewares=[default-auth-missing-secret-rule-0-path-0-retry] service="default-auth-missing-secret-whoami-80" ``` The same behavior reproduces on both current `master` and `v3.7.1`. I also tested a matrix of auth-secret resolution failures. In each error case, Traefik still emitted the backend router without BasicAuth/DigestAuth: - missing `auth-secret` - omitted/empty `auth-secret` - invalid `auth-secret-type` - `auth-file` Secret missing the required `auth` key - empty `auth-map` Secret - missing DigestAuth Secret - cross-namespace `auth-secret` denied by default policy The same matrix includes a positive control where a valid `auth-file` Secret correctly attaches BasicAuth, confirming that the harness is exercising the intended provider path. I also performed a clean-room revalidation from fresh `git archive` source trees for both source/master and v3.7.1. Only the two minimal test harnesses were copied into each archived source tree. This avoided contamination from lab compose files, Docker provider state, dashboard/API routes, prior source-tree test files, or running lab backends. ### Threat model This does not require an attacker to modify Traefik static configuration or Traefik process state. The relevant security boundary is the Kubernetes-declared route policy: an Ingress explicitly declares BasicAuth/DigestAuth, but Traefik publishes the data-plane route without that control when the auth dependency is invalid. In multi-tenant or GitOps-managed clusters, the actor or automation that can affect Secret existence, Secret contents, namespace policy, or deployment ordering is not necessarily the same actor that owns the protected backend or Traefik deployment. As a result, a mistake, rollback, pruning job, policy change, or compromise limited to Kubernetes application resources can remove the effective auth boundary while the Ingress continues to declare that auth is required. ### Impact This is a fail-open authentication control issue leading to unintended unauthenticated route exposure. The trigger is an invalid or unresolved auth dependency, but the security consequence is a data-plane route that violates explicit auth intent. This is materially different from intentionally deploying an unprotected route: the Ingress declares `auth-type: basic` or `digest`, yet Traefik publishes the backend without the corresponding auth middleware. Realistic scenarios include: - GitOps, Helm, or CI/CD deploys Ingress and Secret resources separately. Ordering issues, rollbacks, pruning, or typos can leave the Ingress active while the auth Secret is absent or unreadable. - Kubernetes RBAC commonly separates ownership of Ingress objects, Secrets, and namespace policies. A lower-privileged namespace actor or deployment automation may be able to affect the referenced Secret or cross-namespace reference outcome without having direct access to Traefik static configuration. - During ingress-nginx migration, operators reasonably expect supported `nginx.ingress.kubernetes.io/auth-*` annotations to preserve the authentication boundary. Publishing the backend without auth is a worse failure mode than rejecting the invalid location. - A transient Secret deletion, malformed Secret update, or policy change can turn an already protected route into an unprotected route without changing the Ingress rule itself. Controller logs are not a sufficient mitigation. Logs do not prevent exposure, may not page the service owner, and the first externally visible symptom can be unauthenticated access to the protected backend. ### Suggested remediation Fail closed on any `resolveBasicAuth` error. A minimal tested change is to mark the location as errored: ```diff if err != nil { logger.Error(). Err(err). Str("ingress", fmt.Sprintf("%s/%s rule-%d path-%d", ing.Namespace, ing.Name, ri, pi)). Msg("Cannot resolve auth secret, skipping auth middleware") + loc.Error = true } else { ``` This reuses the existing `loc.Error` / `unavailable-service` path. In my local validation, this change made the no-backend-without-auth regression pass while preserving the valid-secret positive control. </details> ---

### Impact The built-in cURL handlers (`GuzzleHttp\Handler\CurlHandler` and `GuzzleHttp\Handler\CurlMultiHandler`, used by default whenever the PHP cURL extension is available) accept an `https://` proxy — a proxy reached over a TLS-encrypted connection — through the `proxy` request option, client-level `proxy` defaults, or proxy environment variables such as `http_proxy`, `https_proxy`, `HTTPS_PROXY`, `all_proxy`, and `ALL_PROXY`. When the installed libcurl does not support HTTPS proxies, behavior depends on the libcurl version/build: - libcurl older than 7.50.2 silently treats an `https://` proxy as a plaintext `http://` proxy. The TLS connection to the proxy is never established, and the proxy leg is cleartext with no error or warning. - libcurl 7.50.2 through 7.51.x rejects the unsupported proxy scheme at connect time, so no cleartext exposure occurs, but the failure is late and opaque. - libcurl 7.52.0 or newer builds without HTTPS-proxy support also fail at connect time rather than downgrading. The security-relevant case is the silent downgrade on libcurl older than 7.50.2. An application is affected when it sends requests through one of the built-in cURL handlers, configures an `https://` proxy expecting the proxy connection itself to be encrypted, and runs with libcurl older than 7.50.2. In that configuration, traffic expected to be protected by TLS on the hop to the proxy is transmitted in cleartext. Proxy authentication credentials (the `Proxy-Authorization` header, proxy userinfo in the proxy URL, or `CURLOPT_PROXYUSERPWD`) are sent without encryption, and the `CONNECT` target host and port for tunneled HTTPS requests are exposed. For plain HTTP requests, request headers and bodies are also exposed on the proxy leg. End-to-end HTTPS requests tunneled through the proxy remain protected by their inner TLS session; the exposure is limited to the proxy negotiation and proxy credentials. Applications that do not configure an `https://` proxy are not affected. Installations running libcurl 7.52.0 or newer built with HTTPS-proxy support are not affected because HTTPS proxies work as intended. Installations running libcurl 7.50.2 through 7.51.x, or libcurl 7.52.0 or newer built without HTTPS-proxy support, are not exposed to the silent cleartext downgrade, but Guzzle now rejects those unsupported configurations up front as well. The built-in stream handler is not affected; the issue is specific to the cURL handlers' proxy handling. Low-level cURL options under the `curl` request option, such as `CURLOPT_PROXY` or `CURLOPT_PROXYTYPE`, are advanced custom configuration and remain the caller's responsibility. ### Patches The issue is patched in `7.12.1` and later. Starting in that release, the built-in cURL handlers detect whether the installed libcurl supports HTTPS proxies — requiring both libcurl 7.52.0 or newer and the `CURL_VERSION_HTTPS_PROXY` feature bit — and reject a request configured through Guzzle's first-class proxy handling with an `https://` proxy up front by throwing a `GuzzleHttp\Exception\RequestException`. No request bytes reach the network when the proxy cannot be used securely. Versions before `7.12.1` are affected by the silent downgrade when run against libcurl older than 7.50.2. ### Workarounds If you cannot upgrade immediately, do not configure an `https://` proxy on an installation whose libcurl lacks HTTPS-proxy support, and verify the capability in application code before using one. Remember to check proxy environment variables as well as any explicit `proxy` option: ```php $curl = \curl_version(); $httpsProxyBit = \defined('CURL_VERSION_HTTPS_PROXY') ? \CURL_VERSION_HTTPS_PROXY : (1 << 21); if (\version_compare($curl['version'], '7.52.0', '<') || 0 === ($curl['features'] & $httpsProxyBit)) { throw new \RuntimeException('Installed libcurl does not support HTTPS proxies.'); } ``` Upgrading the system libcurl to 7.52.0 or newer built with HTTPS-proxy support also resolves the underlying unsupported-proxy behavior.