Description
Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent has a use-after-free in buffer.c when evbuffer_add_buffer_reference processes an output buffer whose out_total_len is zero. evbuffer_free_all_chains frees the initial empty chain without resetting outbuf->first, outbuf->last, or outbuf->last_with_datap, and APPEND_CHAIN_MULTICAST subsequently dereferences the dangling chain pointer. A caller that can drive this buffer state can cause memory corruption or a process crash. This issue is fixed in versions 2.1.13 and 2.2.2-alpha.
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-c2pj-cg4r-88c8 ↗
- https://github.com/libevent/libevent/commit/5cb95ba2f804f8aff46f88d58391c71e1251cd1c ↗
- https://github.com/libevent/libevent/commit/9db091b04f569be3a700fa9860ef02f90b830af9 ↗
- https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable ↗
- https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha ↗