Envoyproxy Envoy

Envoy v1.33.12-1.36.2 mTLS Cert Matcher Null Byte Bypass
CVE-2025-66220 5 - Medium - December 03, 2025

Envoy is a high-performance edge/middle/service proxy. In 1.33.12, 1.34.10, 1.35.6, 1.36.2, and earlier, Envoys mTLS certificate matcher for match_typed_subject_alt_names may incorrectly treat certificates containing an embedded null byte (\0) inside an OTHERNAME SAN value as valid matches.

Improper Null Termination

Early CONNECT Data Forwarding in Envoy TCP Proxy (v<=1.36.2)
CVE-2025-64763 3.7 - Low - December 03, 2025

Envoy is a high-performance edge/middle/service proxy. In 1.33.12, 1.34.10, 1.35.6, 1.36.2, and earlier, when Envoy is configured in TCP proxy mode to handle CONNECT requests, it accepts client data before issuing a 2xx response and forwards that data to the upstream TCP connection. If a forwarding proxy upstream from Envoy then responds with a non-2xx status, this can cause a de-synchronized CONNECT tunnel state. By default Envoy continues to allow early CONNECT data to avoid disrupting existing deployments. The envoy.reloadable_features.reject_early_connect_data runtime flag can be set to reject CONNECT requests that send data before a 2xx response when intermediaries upstream from Envoy may reject establishment of a CONNECT tunnel.

Protection Mechanism Failure

Envoy 1.33-1.36.2: JWKS Reentry Bug Causes Crash with Multiple JWTs
CVE-2025-64527 6.5 - Medium - December 03, 2025

Envoy is a high-performance edge/middle/service proxy. In 1.33.12, 1.34.10, 1.35.6, 1.36.2, and earlier, Envoy crashes when JWT authentication is configured with the remote JWKS fetching, allow_missing_or_failed is enabled, multiple JWT tokens are present in the request headers and the JWKS fetch fails. This is caused by a re-entry bug in the JwksFetcherImpl. When the first token's JWKS fetch fails, onJwksError() callback triggers processing of the second token, which calls fetch() again on the same fetcher object. The original callback's reset() then clears the second fetch's state (receiver_ and request_) which causes a crash when the async HTTP response arrives.

NULL Pointer Dereference

Envoy Lua Filter UAF pre-1.36.2 causes crash
CVE-2025-62504 6.5 - Medium - October 16, 2025

Envoy is an open source edge and service proxy. Envoy versions earlier than 1.36.2, 1.35.6, 1.34.10, and 1.33.12 contain a use-after-free vulnerability in the Lua filter. When a Lua script executing in the response phase rewrites a response body so that its size exceeds the configured per_connection_buffer_limit_bytes (default 1MB), Envoy generates a local reply whose headers override the original response headers, leaving dangling references and causing a crash. This results in denial of service. Updating to versions 1.36.2, 1.35.6, 1.34.10, or 1.33.12 fixes the issue. Increasing per_connection_buffer_limit_bytes (and for HTTP/2 the initial_stream_window_size) or increasing per_request_buffer_limit_bytes / request_body_buffer_limit can reduce the likelihood of triggering the condition but does not correct the underlying memory safety flaw.

Dangling pointer

Envoy TCP ConnPool Crash <1.36.1 via nullptr Buffer Watermark
CVE-2025-62409 - October 16, 2025

Envoy is a cloud-native, open source edge and service proxy. Prior to 1.36.1, 1.35.5, 1.34.9, and 1.33.10, large requests and responses can potentially trigger TCP connection pool crashes due to flow control management in Envoy. It will happen when the connection is closing but upstream data is still coming, resulting in a buffer watermark callback nullptr reference. The vulnerability impacts TCP proxy and HTTP 1 & 2 mixed use cases based on ALPN. This vulnerability is fixed in 1.36.1, 1.35.5, 1.34.9, and 1.33.10.

NULL Pointer Dereference

Envoy URI Template Matcher USDV: '*'-exclusion bypass RBAC before v1.34.1
CVE-2025-46821 - May 07, 2025

Envoy is a cloud-native edge/middle/service proxy. Prior to versions 1.34.1, 1.33.3, 1.32.6, and 1.31.8, Envoy's URI template matcher incorrectly excludes the `*` character from a set of valid characters in the URI path. As a result URI path containing the `*` character will not match a URI template expressions. This can result in bypass of RBAC rules when configured using the `uri_template` permissions. This vulnerability is fixed in Envoy versions v1.34.1, v1.33.3, v1.32.6, v1.31.8. As a workaround, configure additional RBAC permissions using `url_path` with `safe_regex` expression.

Overly Restrictive Regular Expression

Envoy ext_proc filter crash via local reply before 1.33.1/1.32.4/1.31.6/1.30.10
CVE-2025-30157 7.5 - High - March 21, 2025

Envoy is a cloud-native high-performance edge/middle/service proxy. Prior to 1.33.1, 1.32.4, 1.31.6, and 1.30.10, Envoy's ext_proc HTTP filter is at risk of crashing if a local reply is sent to the external server due to the filter's life time issue. A known situation is the failure of a websocket handshake will trigger a local reply leading to the crash of Envoy. This vulnerability is fixed in 1.33.1, 1.32.4, 1.31.6, and 1.30.10.

Improper Cleanup on Thrown Exception

Envoy Proxy Happy Eyeballs Algorithm Crash Vulnerability
CVE-2024-53269 - December 18, 2024

Envoy is a cloud-native high-performance edge/middle/service proxy. When additional address are not ip addresses, then the Happy Eyeballs sorting algorithm will crash in data plane. This issue has been addressed in releases 1.32.2, 1.31.4, and 1.30.8. Users are advised to upgrade. Users unable to upgrade may disable Happy Eyeballs and/or change the IP configuration.

Always-Incorrect Control Flow Implementation

Envoy Proxy Null Pointer Dereference Vulnerability in HTTP/1 Server Abort Dispatch
CVE-2024-53270 - December 18, 2024

Envoy is a cloud-native high-performance edge/middle/service proxy. In affected versions `sendOverloadError` is going to assume the active request exists when `envoy.load_shed_points.http1_server_abort_dispatch` is configured. If `active_request` is nullptr, only onMessageBeginImpl() is called. However, the `onMessageBeginImpl` will directly return ok status if the stream is already reset leading to the nullptr reference. The downstream reset can actually happen during the H/2 upstream reset. As a result envoy may crash. This issue has been addressed in releases 1.32.3, 1.31.5, 1.30.9, and 1.29.12. Users are advised to upgrade. Users unable to upgrade may disable `http1_server_abort_dispatch` load shed point and/or use a high threshold.

Always-Incorrect Control Flow Implementation

Envoy HTTP/1.1 Non-101 1xx Response Handling Vulnerability
CVE-2024-53271 - December 18, 2024

Envoy is a cloud-native high-performance edge/middle/service proxy. In affected versions envoy does not properly handle http 1.1 non-101 1xx responses. This can lead to downstream failures in networked devices. This issue has been addressed in versions 1.31.5 and 1.32.3. Users are advised to upgrade. There are no known workarounds for this issue.

Always-Incorrect Control Flow Implementation

Envoy Header Manipulation via RFC1918 Trust (fixed v1.31.2+)
CVE-2024-45806 6.5 - Medium - September 20, 2024

Envoy is a cloud-native high-performance edge/middle/service proxy. A security vulnerability in Envoy allows external clients to manipulate Envoy headers, potentially leading to unauthorized access or other malicious actions within the mesh. This issue arises due to Envoy's default configuration of internal trust boundaries, which considers all RFC1918 private address ranges as internal. The default behavior for handling internal addresses in Envoy has been changed. Previously, RFC1918 IP addresses were automatically considered internal, even if the internal_address_config was empty. The default configuration of Envoy will continue to trust internal addresses while in this release and it will not trust them by default in next release. If you have tooling such as probes on your private network which need to be treated as trusted (e.g. changing arbitrary x-envoy headers) please explicitly include those addresses or CIDR ranges into `internal_address_config`. Successful exploitation could allow attackers to bypass security controls, access sensitive data, or disrupt services within the mesh, like Istio. This issue has been addressed in versions 1.31.2, 1.30.6, 1.29.9, and 1.28.7. Users are advised to upgrade. There are no known workarounds for this vulnerability.

Insecure Direct Object Reference / IDOR

Envoy 1.31 Crash via oghttp2 HTTP/2 Codec Bug
CVE-2024-45807 7.5 - High - September 20, 2024

Envoy is a cloud-native high-performance edge/middle/service proxy. Envoy's 1.31 is using `oghttp` as the default HTTP/2 codec, and there are potential bugs around stream management in the codec. To resolve this Envoy will switch off the `oghttp2` by default. The impact of this issue is that envoy will crash. This issue has been addressed in release version 1.31.2. All users are advised to upgrade. There are no known workarounds for this issue.

Always-Incorrect Control Flow Implementation

Envoy - ACCESSLOG Injection via REQUESTED_SERVER_NAME (fixed 1.31.2+)
CVE-2024-45808 6.5 - Medium - September 20, 2024

Envoy is a cloud-native high-performance edge/middle/service proxy. A vulnerability has been identified in Envoy that allows malicious attackers to inject unexpected content into access logs. This is achieved by exploiting the lack of validation for the `REQUESTED_SERVER_NAME` field for access loggers. This issue has been addressed in versions 1.31.2, 1.30.6, 1.29.9, and 1.28.7. Users are advised to upgrade. There are no known workarounds for this vulnerability.

Output Sanitization

Envoy JWT Filter Crash via clear_route_cache (fixed 1.31.2, 1.30.6, 1.29.9)
CVE-2024-45809 7.5 - High - September 20, 2024

Envoy is a cloud-native high-performance edge/middle/service proxy. Jwt filter will lead to an Envoy crash when clear route cache with remote JWKs. In the following case: 1. remote JWKs are used, which requires async header processing; 2. clear_route_cache is enabled on the provider; 3. header operations are enabled in JWT filter, e.g. header to claims feature; 4. the routing table is configured in a way that the JWT header operations modify requests to not match any route. When these conditions are met, a crash is triggered in the upstream code due to nullptr reference conversion from route(). The root cause is the ordering of continueDecoding and clearRouteCache. This issue has been addressed in versions 1.31.2, 1.30.6, and 1.29.9. Users are advised to upgrade. There are no known workarounds for this vulnerability.

NULL Pointer Dereference

Envoy 1.31.2+ / 1.30.6 / 1.29.9 / 1.28.7 fix async client crash on sendLocalReply
CVE-2024-45810 6.5 - Medium - September 20, 2024

Envoy is a cloud-native high-performance edge/middle/service proxy. Envoy will crash when the http async client is handling `sendLocalReply` under some circumstance, e.g., websocket upgrade, and requests mirroring. The http async client will crash during the `sendLocalReply()` in http async client, one reason is http async client is duplicating the status code, another one is the destroy of router is called at the destructor of the async stream, while the stream is deferred deleted at first. There will be problems that the stream decoder is destroyed but its reference is called in `router.onDestroy()`, causing segment fault. This will impact ext_authz if the `upgrade` and `connection` header are allowed, and request mirrorring. This issue has been addressed in versions 1.31.2, 1.30.6, 1.29.9, and 1.28.7. Users are advised to upgrade. There are no known workarounds for this vulnerability.

Buffer Overflow

Envoy Proxy: Authenticated Cmd Exec via Weak Encrypted Upload
CVE-2024-21881 - August 12, 2024

Inadequate Encryption Strength vulnerability allow an authenticated attacker to execute arbitrary OS Commands via encrypted package upload.This issue affects Envoy: 4.x and 5.x

Envoy Memory Reuse in Route Hash Policy Cookie Attribute (1.30.3)
CVE-2024-39305 - July 01, 2024

Envoy is a cloud-native, open source edge and service proxy. Prior to versions 1.30.4, 1.29.7, 1.28.5, and 1.27.7. Envoy references already freed memory when route hash policy is configured with cookie attributes. Note that this vulnerability has been fixed in the open as the effect would be immediately apparent if it was configured. Memory allocated for holding attribute values is freed after configuration was parsed. During request processing Envoy will attempt to copy content of de-allocated memory into request cookie header. This can lead to arbitrary content of Envoy's memory to be sent to the upstream service or abnormal process termination. This vulnerability is fixed in Envoy versions v1.30.4, v1.29.7, v1.28.5, and v1.27.7. As a workaround, do not use cookie attributes in route action hash policy.

Envoy JSON Exception Crash CVE-2024-34363
CVE-2024-34363 7.5 - High - June 04, 2024

Envoy is a cloud-native, open source edge and service proxy. Due to how Envoy invoked the nlohmann JSON library, the library could throw an uncaught exception from downstream data if incomplete UTF-8 strings were serialized. The uncaught exception would cause Envoy to crash.

Envoy OOM via Mirror Response Unbounded Buffer Abuse
CVE-2024-34364 6.5 - Medium - June 04, 2024

Envoy is a cloud-native, open source edge and service proxy. Envoy exposed an out-of-memory (OOM) vector from the mirror response, since async HTTP client will buffer the response with an unbounded buffer.

Memory Corruption

Envoy Proxy Crash via Integer Underflow in QuicStreamSequencerBuffer
CVE-2024-32975 7.5 - High - June 04, 2024

Envoy is a cloud-native, open source edge and service proxy. There is a crash at `QuicheDataReader::PeekVarInt62Length()`. It is caused by integer underflow in the `QuicStreamSequencerBuffer::PeekRegion()` implementation.

Integer underflow

Envoy HCM Use-After-Free Crash via QUIC Reset
CVE-2024-34362 5.9 - Medium - June 04, 2024

Envoy is a cloud-native, open source edge and service proxy. There is a use-after-free in `HttpConnectionManager` (HCM) with `EnvoyQuicServerStream` that can crash Envoy. An attacker can exploit this vulnerability by sending a request without `FIN`, then a `RESET_STREAM` frame, and then after receiving the response, closing the connection.

Dangling pointer

EnvoyProxy: Endless Loop in Brotli Decompression Filter
CVE-2024-32976 7.5 - High - June 04, 2024

Envoy is a cloud-native, open source edge and service proxy. Envoyproxy with a Brotli filter can get into an endless loop during decompression of Brotli data with extra input.

Infinite Loop

Envoy UAF via QUICHE in QuicServerStream (CVE-2024-32974)
CVE-2024-32974 7.5 - High - June 04, 2024

Envoy is a cloud-native, open source edge and service proxy. A crash was observed in `EnvoyQuicServerStream::OnInitialHeadersComplete()` with following call stack. It is a use-after-free caused by QUICHE continuing push request headers after `StopReading()` being called on the stream. As after `StopReading()`, the HCM's `ActiveStream` might have already be destroyed and any up calls from QUICHE could potentially cause use after free.

Dangling pointer

Envoy request smuggling via 200/101 upgrade mismatch
CVE-2024-23326 8.2 - High - June 04, 2024

Envoy is a cloud-native, open source edge and service proxy. A theoretical request smuggling vulnerability exists through Envoy if a server can be tricked into adding an upgrade header into a response. Per RFC https://www.rfc-editor.org/rfc/rfc7230#section-6.7 a server sends 101 when switching protocols. Envoy incorrectly accepts a 200 response from a server when requesting a protocol upgrade, but 200 does not indicate protocol switch. This opens up the possibility of request smuggling through Envoy if the server can be tricked into adding the upgrade header to the response.

HTTP Request Smuggling

Envoy HTTP/2 CONTINUATION Flood CVE-2024-30255 CPU Exhaustion before 1.29.3
CVE-2024-30255 5.3 - Medium - April 04, 2024

Envoy is a cloud-native, open source edge and service proxy. The HTTP/2 protocol stack in Envoy versions prior to 1.29.3, 1.28.2, 1.27.4, and 1.26.8 are vulnerable to CPU exhaustion due to flood of CONTINUATION frames. Envoy's HTTP/2 codec allows the client to send an unlimited number of CONTINUATION frames even after exceeding Envoy's header map limits. This allows an attacker to send a sequence of CONTINUATION frames without the END_HEADERS bit set causing CPU utilization, consuming approximately 1 core per 300Mbit/s of traffic and culminating in denial of service through CPU exhaustion. Users should upgrade to version 1.29.3, 1.28.2, 1.27.4, or 1.26.8 to mitigate the effects of the CONTINUATION flood. As a workaround, disable HTTP/2 protocol for downstream connections.

Detection of Error Condition Without Action

Envoy 1.29.01.29.1 HTTP/2 codec CONTINUATION Flood DoS Vulnerability
CVE-2024-27919 7.5 - High - April 04, 2024

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.

Detection of Error Condition Without Action

Envoy Crash on Timeout Misconfig (before 1.29.1)
CVE-2024-23322 7.5 - High - February 09, 2024

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.

Dangling pointer

Envoy Regex Compile Causing High CPU Leaks Fixed in 1.29.1/1.28.1
CVE-2024-23323 5.3 - Medium - February 09, 2024

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.

Resource Exhaustion

Envoy External Auth Bypass CVE-2024-23324 Fixed in 1.29.1,1.28.1,1.27.3,1.26.7
CVE-2024-23324 7.5 - High - February 09, 2024

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.

Envoy Proxy Protocol Crash on IPv6 via IPv4 (before 1.29.1)
CVE-2024-23325 7.5 - High - February 09, 2024

Envoy is a high-performance edge/middle/service proxy. Envoy crashes in Proxy protocol when using an address type that isnt 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.

Improper Handling of Exceptional Conditions

Envoy PPv2 Header Segfault CVE-2024-23327 (before1.29.1)
CVE-2024-23327 7.5 - High - February 09, 2024

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.

NULL Pointer Dereference

HTTP/2 DoS via Stream Reset in nginx
CVE-2023-44487 7.5 - High - October 10, 2023

The HTTP/2 protocol allows a denial of service (server resource consumption) because request cancellation can reset many streams quickly, as exploited in the wild in August through October 2023.

Resource Exhaustion

Envoy V<1.27: Mixed-case HTTP/2 scheme bypass
CVE-2023-35944 5.3 - Medium - July 25, 2023

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.

HTTP Request Smuggling

Envoy <1.27.0 gRPC Use-After-Free Caused by Access Logger Listener Drain
CVE-2023-35942 6.5 - Medium - July 25, 2023

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.

Dangling pointer

Envoy CORS segfault before 1.27 due to missing Origin header
CVE-2023-35943 7.5 - High - July 25, 2023

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.

Dangling pointer

Envoy <1.27.0 Eternal OAuth2 HMAC Validity via Wildcards
CVE-2023-35941 9.8 - Critical - July 25, 2023

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.

Output Sanitization

Envoy HTTP/2 Codec Memory Leak via RST_STREAM+GOAWAY Frames (Fixed in 1.26.3)
CVE-2023-35945 7.5 - High - July 13, 2023

Envoy is a cloud-native high-performance edge/middle/service proxy. Envoys 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.

Insufficient Cleanup

Envoy Request Header Injection (1.26.0, 1.25.3, 1.24.4, 1.23.6, 1.22.9)
CVE-2023-27493 9.1 - Critical - April 04, 2023

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 Envoys 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.

HTTP Request Smuggling

Envoy OAuth Filter Crash via Missing State Param (1.26.0)
CVE-2023-27496 7.5 - High - April 04, 2023

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).

Envoy 1.26/1.25/1.24 HTTP/1 Malformed Request Line Bypass
CVE-2023-27491 9.1 - Critical - April 04, 2023

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.

HTTP Request Smuggling

Envoy Lua Filter DoS Pre1.26 (Large Body Crash)
CVE-2023-27492 6.5 - Medium - April 04, 2023

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.

Allocation of Resources Without Limits or Throttling

Envoy 1.x PrivEsc via ext_authz FailureModeAllow Missed UTF-8 gRPC
CVE-2023-27488 9.8 - Critical - April 04, 2023

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`.

Envoy JWT Auth Bypass via x-envoy-original-path (1.25.31.26.0)
CVE-2023-27487 9.1 - Critical - April 04, 2023

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.

Envoy is a cloud-native high-performance proxy
CVE-2022-29226 9.1 - Critical - June 09, 2022

Envoy is a cloud-native high-performance proxy. In versions prior to 1.22.1 the OAuth filter implementation does not include a mechanism for validating access tokens, so by design when the HMAC signed cookie is missing a full authentication flow should be triggered. However, the current implementation assumes that access tokens are always validated thus allowing access in the presence of any access token attached to the request. Users are advised to upgrade. There is no known workaround for this issue.

Missing Authentication for Critical Function

Envoy is a cloud-native high-performance edge/middle/service proxy
CVE-2022-29227 7.5 - High - June 09, 2022

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, thereâs 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.

Dangling pointer

Envoy is a cloud-native high-performance proxy
CVE-2022-29228 7.5 - High - June 09, 2022

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() shouldnât 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.

Dangling pointer

Envoy is a cloud-native high-performance proxy
CVE-2022-29225 7.5 - High - June 09, 2022

Envoy is a cloud-native high-performance proxy. In versions prior to 1.22.1 secompressors accumulate decompressed data into an intermediate buffer before overwriting the body in the decode/encodeBody. This may allow an attacker to zip bomb the decompressor by sending a small highly compressed payload. Maliciously constructed zip files may exhaust system memory and cause a denial of service. Users are advised to upgrade. Users unable to upgrade may consider disabling decompression.

Resource Exhaustion

Envoy is a cloud-native high-performance proxy
CVE-2022-29224 5.9 - Medium - June 09, 2022

Envoy is a cloud-native high-performance proxy. Versions of envoy prior to 1.22.1 are subject to a segmentation fault in the GrpcHealthCheckerImpl. Envoy can perform various types of upstream health checking. One of them uses gRPC. Envoy also has a feature which can âholdâ? (prevent removal) upstream hosts obtained via service discovery until configured active health checking fails. If an attacker controls an upstream host and also controls service discovery of that host (via DNS, the EDS API, etc.), an attacker can crash Envoy by forcing removal of the host from service discovery, and then failing the gRPC health check request. This will crash Envoy via a null pointer dereference. Users are advised to upgrade to resolve this vulnerability. Users unable to upgrade may disable gRPC health checking and/or replace it with a different health checking type as a mitigation.

NULL Pointer Dereference

Envoy is an open source edge and service proxy, designed for cloud-native applications
CVE-2022-23606 6.5 - Medium - February 22, 2022

Envoy is an open source edge and service proxy, designed for cloud-native applications. When a cluster is deleted via Cluster Discovery Service (CDS) all idle connections established to endpoints in that cluster are disconnected. A recursion was introduced in the procedure of disconnecting idle connections that can lead to stack exhaustion and abnormal process termination when a cluster has a large number of idle connections. This infinite recursion causes Envoy to crash. Users are advised to upgrade.

Stack Exhaustion

Envoy is an open source edge and service proxy, designed for cloud-native applications
CVE-2021-43824 7.5 - High - February 22, 2022

Envoy is an open source edge and service proxy, designed for cloud-native applications. In affected versions a crafted request crashes Envoy when a CONNECT request is sent to JWT filter configured with regex match. This provides a denial of service attack vector. The only workaround is to not use regex in the JWT filter. Users are advised to upgrade.

NULL Pointer Dereference