Input validation error in envoy - CVE-2021-29492
Published: May 11, 2021 / Updated: August 26, 2026
Vulnerability identifier: #VU145849
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2021-29492
CWE-ID: CWE-20
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to bypass path matching rules.
The vulnerability exists due to improper input validation in path matching rules when handling request paths containing escaped slash characters. A remote attacker can send a specially crafted request to bypass path matching rules.
Affected software
envoy
How to mitigate CVE-2021-29492
Install security update from vendor's website.
envoy - addressed in versions 1.15.5, 1.16.4, 1.17.3, 1.18.3