Vulnerability in Envoyproxy Envoy

CVE-2024-23326

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.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.004 (27.4th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 27th percentile — 27.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2024-23326: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

  • Envoyproxy Envoy — versions >= 1.13.0, <= 1.30.1, >= 1.29.0, <= 1.29.4, >= 1.28.0, <= 1.28.3

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2024-23326?
CVE-2024-23326 is a medium-severity vulnerability in Envoyproxy Envoy, classified under CWE-391. CVSS score: 5.9/10. Published 2024-06-04.
How severe is CVE-2024-23326?
Medium severity. CVSS v3 base score is 5.9 out of 10.