Description
Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent has two HTTP parsing weaknesses in http.c. evhttp_decode_uri_internal decodes percent-encoded %00 bytes into literal NUL characters, which can cause downstream C string operations to truncate a path and bypass validation performed on a different representation. evhttp_header_is_valid_value also accepts obsolete line folding in header values containing carriage return or line feed characters, allowing a proxy and libevent to interpret headers differently and enabling header injection or access control bypass. The CRLF header acceptance is fixed in versions 2.1.13 and 2.2.2-alpha, but the reviewed patches do not clearly remediate the URI NUL-truncation condition.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
libevent libevent
>= 2.2.0-alpha, < 2.2.2-alphaaffected< 2.1.13affected
References
- https://github.com/libevent/libevent/security/advisories/GHSA-jcwh-pvf2-73p2 ↗
- https://github.com/libevent/libevent/commit/758be0c0f69c1934ef9a84ab39e9f9e5fde2e6d0 ↗
- https://github.com/libevent/libevent/commit/9170dd35e64714613e8d13b290587cfc28e258e2 ↗
- https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable ↗
- https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha ↗