CVEvulnerability

CVE-2021-32777

8.3 HIGH Published 2021-08-24 Modified 2026-06-17 Official page ↗
Status
Modified
Published
2021-08-24
Last modified
2026-06-17
Assigner
[email protected]
CVSS 3.1 ([email protected])
8.6 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
CVSS 3.1 ([email protected])
8.3 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:L
CVSS 2.0 ([email protected])
7.5 HIGH — AV:N/AC:L/Au:N/C:P/I:P/A:P
Weaknesses
CWE-551, CWE-863

Description

Envoy is an open source L7 proxy and communication bus designed for large modern service oriented architectures. In affected versions when ext-authz extension is sending request headers to the external authorization service it must merge multiple value headers according to the HTTP spec. However, only the last header value is sent. This may allow specifically crafted requests to bypass authorization. Attackers may be able to escalate privileges when using ext-authz extension or back end service that uses multiple value headers for authorization. A specifically constructed request may be delivered by an untrusted downstream peer in the presence of ext-authz extension. Envoy versions 1.19.1, 1.18.4, 1.17.4, 1.16.5 contain fixes to the ext-authz extension to correctly merge multiple request header values, when sending request for authorization.

Affected configurations

• envoyproxy envoy (>= 1.16.0 < 1.16.5) • envoyproxy envoy (>= 1.17.0 < 1.17.4) • envoyproxy envoy (>= 1.18.0 < 1.18.4) • envoyproxy envoy 1.19.0

Related

Weakness · CWE (2)

  • CWE-551 Incorrect Behavior Order: Authorization Before Parsing and Canonicalization weakness
  • CWE-863 Incorrect Authorization weakness

References