Envoy

Envoy is a cloud-native, open-source edge and service proxy. In versions 1.29.0 and 1.29.1, theEnvoy HTTP/2 protocol stack is vulnerable to the flood of CONTINUATION frames. Envoy's HTTP/2 codec does not reset a request when header map limits have been exceeded. This allows an attacker to send an sequence of CONTINUATION frames without the END_HEADERS bit set causing unlimited memory consumption. This can lead to denial of service through memory exhaustion. Users should upgrade to versions 1.29.2 to mitigate the effects of the CONTINUATION flood. Note that this vulnerability is a regression in Envoy version 1.29.0 and 1.29.1 only. As a workaround, downgrade to version 1.28.1 or earlier or disable HTTP/2 protocol for downstream connections.Show less

Envoy is a high-performance edge/middle/service proxy. When PPv2 is enabled both on a listener and subsequent cluster, the Envoy instance will segfault when attempting to craft the upstream PPv2 header. This occurs when the downstream request has a command type of LOCAL and does not have the protocol block. This issue has been addressed in releases 1.29.1, 1.28.1, 1.27.3, and 1.26.7. Users are advised to upgrade. There are no known workarounds for this vulnerability.Show less

Envoy is a high-performance edge/middle/service proxy. Envoy crashes in Proxy protocol when using an address type that isn’t supported by the OS. Envoy is susceptible to crashing on a host with IPv6 disabled and a listener config with proxy protocol enabled when it receives a request where the client presents its IPv6 address. It is valid for a client to present its IPv6 address to a target server even though the whole chain is connected via IPv4. This issue has been addressed in released 1.29.1, 1.28.1, 1.27.3, and 1.26.7. Users are advised to upgrade. There are no known workarounds for this vulnerability.Show less

Envoy is a high-performance edge/middle/service proxy. External authentication can be bypassed by downstream connections. Downstream clients can force invalid gRPC requests to be sent to ext_authz, circumventing ext_authz checks when failure_mode_allow is set to true. This issue has been addressed in released 1.29.1, 1.28.1, 1.27.3, and 1.26.7. Users are advised to upgrade. There are no known workarounds for this vulnerability. Show less

Envoy is a high-performance edge/middle/service proxy. The regex expression is compiled for every request and can result in high CPU usage and increased request latency when multiple routes are configured with such matchers. This issue has been addressed in released 1.29.1, 1.28.1, 1.27.3, and 1.26.7. Users are advised to upgrade. There are no known workarounds for this vulnerability.Show less

Envoy is a high-performance edge/middle/service proxy. Envoy will crash when certain timeouts happen within the same interval. The crash occurs when the following are true: 1. hedge_on_per_try_timeout is enabled, 2. per_try_idle_timeout is enabled (it can only be done in configuration), 3. per-try-timeout is enabled, either through headers or configuration and its value is equal, or within the backoff interval of the per_try_idle_timeout. This issue has been addressed in released 1.29.1, 1.28.1, 1.27.3, and 1.26.7. Users are advised to upgrade. There are no known workarounds for this vulnerability.Show less

Envoy is an open source edge and service proxy designed for cloud-native applications. Envoy allows mixed-case schemes in HTTP/2, however, some internal scheme checks are case-sensitive. Prior to versions 1.27.0, 1.26.4, 1.25.9, 1.24.10, and 1.23.12, this can lead to the rejection of requests with mixed-case schemes such as `htTp` or `htTps`, or the bypassing of some requests such as `https` in unencrypted connections. With a fix in versions 1.27.0, 1.26.4, 1.25.9, 1.24.10, and 1.23.12, Envoy will now lowercase scheme values by default, and change the internal scheme checks that were case-sensitive to be case-insensitive. There are no known workarounds for this issue.Show less

Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to versions 1.27.0, 1.26.4, 1.25.9, 1.24.10, and 1.23.12, the CORS filter will segfault and crash Envoy when the `origin` header is removed and deleted between `decodeHeaders`and `encodeHeaders`. Versions 1.27.0, 1.26.4, 1.25.9, 1.24.10, and 1.23.12 have a fix for this issue. As a workaround, do not remove the `origin` header in the Envoy configuration.Show less

Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to versions 1.27.0, 1.26.4, 1.25.9, 1.24.10, and 1.23.12, gRPC access loggers using listener's global scope can cause a `use-after-free` crash when the listener is drained. Versions 1.27.0, 1.26.4, 1.25.9, 1.24.10, and 1.23.12 have a fix for this issue. As a workaround, disable gRPC access log or stop listener update.Show less

Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to versions 1.27.0, 1.26.4, 1.25.9, 1.24.10, and 1.23.12, a malicious client is able to construct credentials with permanent validity in some specific scenarios. This is caused by the some rare scenarios in which HMAC payload can be always valid in OAuth2 filter's check. Versions 1.27.0, 1.26.4, 1.25.9, 1.24.10, and 1.23.12 have a fix for this issue. As a workaround, avoid wildcards/prefix domain wildcards in the host's domain configuration.Show less

Envoy is a cloud-native high-performance edge/middle/service proxy. Envoy’s HTTP/2 codec may leak a header map and bookkeeping structures upon receiving `RST_STREAM` immediately followed by the `GOAWAY` frames from an upstream server. In nghttp2, cleanup of pending requests due to receipt of the `GOAWAY` frame skips de-allocation of the bookkeeping structure and pending compressed header. The error return [code path] is taken if connection is already marked for not sending more requests due to `GOAWAY` frame. The clean-up code is right after the return statement, causing memory leak. Denial of service through memory exhaustion. This vulnerability was patched in versions(s) 1.26.3, 1.25.8, 1.24.9, 1.23.11.Show less

Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9, the OAuth filter assumes that a `state` query param is present on any response that looks like an OAuth redirect response. Sending it a request with the URI path equivalent to the redirect path, without the `state` parameter, will lead to abnormal termination of Envoy process. Versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9 contain a patch. The issue can also be mitigated by locking down OAuth traffic, disabling the filter, or by filtering traffic before it reaches the OAuth filter (e.g. via a lua script). Show less

Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9, Envoy does not sanitize or escape request properties when generating request headers. This can lead to characters that are illegal in header values to be sent to the upstream service. In the worst case, it can cause upstream service to interpret the original request as two pipelined requests, possibly bypassing the intent of Envoy’s security policy. Versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9 contain a patch. As a workaround, disable adding request headers based on the downstream request properties, such as downstream certificate properties.Show less

Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9, the Lua filter is vulnerable to denial of service. Attackers can send large request bodies for routes that have Lua filter enabled and trigger crashes. As of versions versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9, Envoy no longer invokes the Lua coroutine if the filter has been reset. As a workaround for those whose Lua filter is buffering all requests/ responses, mitigate by using the buffer filter to avoid triggering the local reply in the Lua filter.Show less

Envoy is an open source edge and service proxy designed for cloud-native applications. Compliant HTTP/1 service should reject malformed request lines. Prior to versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9, There is a possibility that non compliant HTTP/1 service may allow malformed requests, potentially leading to a bypass of security policies. This issue is fixed in versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9.Show less

Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9, escalation of privileges is possible when `failure_mode_allow: true` is configured for `ext_authz` filter. For affected components that are used for logging and/or visibility, requests may not be logged by the receiving service. When Envoy was configured to use ext_authz, ext_proc, tap, ratelimit filters, and grpc access log service and an http header with non-UTF-8 data was received, Envoy would generate an invalid protobuf message and send it to the configured service. The receiving service would typically generate an error when decoding the protobuf message. For ext_authz that was configured with ``failure_mode_allow: true``, the request would have been allowed in this case. For the other services, this could have resulted in other unforeseen errors such as a lack of visibility into requests. As of versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9, Envoy by default sanitizes the values sent in gRPC service calls to be valid UTF-8, replacing data that is not valid UTF-8 with a `!` character. This behavioral change can be temporarily reverted by setting runtime guard `envoy.reloadable_features.service_sanitize_non_utf8_strings` to false. As a workaround, one may set `failure_mode_allow: false` for `ext_authz`.Show less

Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9, the client may bypass JSON Web Token (JWT) checks and forge fake original paths. The header `x-envoy-original-path` should be an internal header, but Envoy does not remove this header from the request at the beginning of request processing when it is sent from an untrusted client. The faked header would then be used for trace logs and grpc logs, as well as used in the URL used for `jwt_authn` checks if the `jwt_authn` filter is used, and any other upstream use of the x-envoy-original-path header. Attackers may forge a trusted `x-envoy-original-path` header. Versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9 have patches for this issue.Show less

Envoy is a cloud-native high-performance proxy. In versions prior to 1.22.1 the OAuth filter would try to invoke the remaining filters in the chain after emitting a local response, which triggers an ASSERT() in newer versions and corrupts memory on earlier versions. continueDecoding() shouldn’t ever be called from filters after a local reply has been sent. Users are advised to upgrade. There are no known workarounds for this issue.Show less

Envoy is a cloud-native high-performance edge/middle/service proxy. In versions prior to 1.22.1 if Envoy attempts to send an internal redirect of an HTTP request consisting of more than HTTP headers, there’s a lifetime bug which can be triggered. If while replaying the request Envoy sends a local reply when the redirect headers are processed, the downstream state indicates that the downstream stream is not complete. On sending the local reply, Envoy will attempt to reset the upstream stream, but as it is actually complete, and deleted, this result in a use-after-free. Users are advised to upgrade. Users unable to upgrade are advised to disable internal redirects if crashes are observed.Show less