Vulnerability · Published Jul 25, 2023 · Assigned by GitHub_M

CVE-2023-35944Envoy vulnerable to incorrect handling of HTTP requests and responses with mixed case schemes

High 8.2

In plain English

A high-severity improper input validation in envoy from envoyproxy. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 54% of all known vulnerabilities).

Severity (CVSS 3.1)8.2High

Exploit odds (30 days)0.7%top 46.5% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

Vendor	Product	Versions
envoyproxy	envoy	>= 1.26.0, < 1.26.4>= 1.25.0, < 1.25.9>= 1.24.0, < 1.24.10< 1.23.12

Weakness: CWE-20 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

References

https://github.com/envoyproxy/envoy/security/advisories/GHSA-pvgm-7jpg-pw5g x_refsource_CONFIRM