CVE Vulnerability

CVE-2021-32777

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.

7.5 /10

CVSS v2.0 :

V3 Legend

Vector :

Exploitability : 10 / Impact : 6.4

Attack Vector

Attack Complexity

Privileges Required

User Interaction

Confidentiality Impact PARTIAL

Integrity Impact PARTIAL

Availability Impact PARTIAL

Scope

8.3 /10

CVSS v3.0 : HIGH

V3 Legend

Vector :

Exploitability : 3.9 / Impact : 3.7

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact LOW

Scope CHANGED

References
Link Resource
https://github.com/envoyproxy/envoy/security/advisories/GHSA-6g4j-5vrw-2m8h Third Party Advisory
https://www.envoyproxy.io/docs/envoy/v1.19.0/version_history/version_history Release Notes Vendor Advisory
Configurations

Configuration 1

cpe:2.3:a:envoyproxy:envoy:1.19.0:*:*:*:*:*:*:*
cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*
cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*
cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*
Information

Published : 2021-08-24 09:15

Updated : 2022-06-15 03:50

NVD link : CVE-2021-32777

Mitre link : CVE-2021-32777

Products Affected
No products.
CWE
CWE-863