CVE-2024-23326: envoyproxy envoy Unchecked Error Condition

Vulnerability summary

CVE-2024-23326 is a high (CVSS 8.2) Unchecked Error Condition vulnerability in envoyproxy envoy. EPSS estimates a 0.36% chance of exploitation in the next 30 days, higher than 28.5% of scored vulnerabilities.

Timeline

1. 04-06-2024
   PublishedVulnerability first disclosed.
2. 01-08-2024
   Last modifiedVulnerability information updated.

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.

• CWE-391Unchecked Error Condition[PLANNED FOR DEPRECATION. SEE MAINTENANCE NOTES AND CONSIDER CWE-252, CWE-248, OR CWE-1069.] Ignoring exceptions and other error conditions may allow an attacker to induce unexpected behavior unnoticed.
• CWE-444Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination.