Envoy Proxy Envoyproxy Envoy

Envoy 1.9.0 and before does not normalize HTTP URL paths. A remote attacker may craft a relative path, e.g., something/../admin, to bypass access control, e.g., a block on /admin. A backend server could then interpret the non-normalized path and provide an attacker access beyond the scope provided for by the access control policy.

Trivial authentication bypass in Envoy

An issue was discovered in Envoy 1.12.0. An untrusted remote client may send HTTP/2 requests that write to the heap outside of the request buffers when the upstream is HTTP/1. This may be used to corrupt nearby heap contents (leading to a query-of-death scenario) or may be used to bypass Envoy's access control mechanisms such as path based routing. An attacker can also modify requests from other users that happen to be proximal temporally and spatially.

An issue was discovered in Envoy 1.12.0. An untrusted remote client may send an HTTP header (such as Host) with whitespace after the header content. Envoy will treat "header-value " as a different string from "header-value" so for example with the Host header "example.com " one could bypass "example.com" matchers.

Incorrect configuration handling allows TLS session re-use without re-validation in Envoy

Envoy vulnerable to OAuth2 credentials exploit with permanent validity

Envoy gRPC client produces invalid protobuf when an HTTP header with non-UTF8 value is received.

Envoy forwards invalid Http2/Http3 downstream headers

Envoy Proxy use after free when route hash policy is configured with cookie attributes

Envoy client may fake the header `x-envoy-original-path`

Envoy doesn't escape HTTP header values

Envoy before 1.16.1 logs an incorrect downstream address because it considers only the directly connected peer, not the information in the proxy protocol header. This affects situations with tcp-proxy as the network filter (not HTTP filters).

Envoy: oAuth2 Filter Signout route will not clear cookies because of missing "secure;" flag

Incorrect concatenation of multiple value request headers in ext-authz extension

Incorrect handling of H2 GOAWAY + SETTINGS frames

Incorrect Authorization with specially crafted requests

Continued processing of requests after locally generated response

Incorrect handling of H/2 GOAWAY followed by SETTINGS frames

Incorrectly handling of URI '#fragment' element as part of the path element

Envoy ext auth can be bypassed when Proxy protocol filter sets invalid UTF-8 metadata

Bypass of path matching rules using escaped slash characters

When parsing HTTP/1.x header values, Envoy 1.9.0 and before does not reject embedded zero characters (NUL, ASCII 0x0). This allows remote attackers crafting header values containing embedded NUL characters to potentially bypass header matching rules, gaining access to unauthorized resources.

Envoy through 1.15.0 only considers the first value when multiple header values are present for some HTTP headers. Envoy’s setCopy() header map API does not replace all existing occurences of a non-inline header.

JWT authentication bypass with unknown issuer token

Envoy vulnerable to incorrect handling of HTTP requests and responses with mixed case schemes

Envoy incorrectly accepts HTTP 200 response for entering upgrade mode

Envoy has an RBAC Header Validation Bypass via Multi-Value Header Concatenation

Upon receiving each incoming request header data, Envoy will iterate over existing request headers to verify that the total size of the headers stays below a maximum limit. The implementation in versions 1.10.0 through 1.11.1 for HTTP/1.x traffic and all versions of Envoy for HTTP/2 traffic had O(n^2) performance characteristics. A remote attacker may craft a request that stays below the maximum request header size but consists of many thousands of small headers to consume CPU and result in a denial-of-service attack.

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.

HTTP/2: CPU exhaustion due to CONTINUATION frame flood

HTTP/2: memory exhaustion due to CONTINUATION frame flood

In Envoy through 1.11.1, users may configure a route to match incoming path headers via the libstdc++ regular expression implementation. A remote attacker may send a request with a very long URI to result in a denial of service (memory consumption). This is a related issue to CVE-2019-14993.

Envoy before 1.16.1 mishandles dropped and truncated datagrams, as demonstrated by a segmentation fault for a UDP packet size larger than 1500.

An issue was discovered in Envoy 1.12.0. Upon receipt of a malformed HTTP request without a Host header, it sends an internally generated "Invalid request" response. This internally generated response is dispatched through the configured encoder filter chain before being sent to the client. An encoder filter that invokes route manager APIs that access a request's Host header causes a NULL pointer dereference, resulting in abnormal termination of the Envoy process.

An issue was discovered in Envoy through 1.71.1. There is a remotely exploitable integer overflow in which a very large grpc-timeout value leads to unexpected timeout calculations.

Envoy 1.12.0 allows a remote denial of service because of resource loops, as demonstrated by a single idle TCP connection being able to keep a worker thread in an infinite busy loop when continue_on_listener_filters_timeout is used."

An issue was discovered in Envoy 1.14.0. There is a remotely exploitable crash for HTTP2 Metadata, because an empty METADATA map triggers a Reachable Assertion.

Envoy version 1.14.2, 1.13.2, 1.12.4 or earlier is susceptible to increased memory usage in the case where an HTTP/2 client requests a large payload but does not send enough window updates to consume the entire stream and does not reset the stream.

An issue was discovered in Envoy through 1.71.1. There is a remotely exploitable NULL pointer dereference and crash in TLS when an unknown TLS alert code is received.

Excessive CPU usage in Pomerium