Vulnerability · Published Jun 4, 2024 · Assigned by GitHub_M

CVE-2024-23326Envoy incorrectly accepts HTTP 200 response for entering upgrade mode

Medium 5.9

In plain English

A medium-severity security flaw in envoy from envoyproxy. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 30% of all known vulnerabilities).

Severity (CVSS 3.1)5.9Medium

Exploit odds (30 days)0.4%top 69.9% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

Envoy is a cloud-native, open source edge and service proxy. A theoretical request smuggling vulnerability exists through Envoy if a server can be tricked into adding an upgrade header into a response. Per RFC https://www.rfc-editor.org/rfc/rfc7230#section-6.7 a server sends 101 when switching protocols. Envoy incorrectly accepts a 200 response from a server when requesting a protocol upgrade, but 200 does not indicate protocol switch. This opens up the possibility of request smuggling through Envoy if the server can be tricked into adding the upgrade header to the response.

Affected products (as reported)

Vendor	Product	Versions
envoyproxy	envoy	>= 1.13.0, <= 1.30.1>= 1.29.0, <= 1.29.4>= 1.28.0, <= 1.28.3<= 1.27.5

Weakness: CWE-391 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

References

https://github.com/envoyproxy/envoy/security/advisories/GHSA-vcf8-7238-v74c x_refsource_CONFIRM