CVE-2024-25629: C-Ares

Medium severity, CVSS 5.5. EPSS: 0.4% chance of exploitation in the next 30 days.

c-ares is a C library for asynchronous DNS requests. `ares__read_line()` is used to parse local configuration files such as `/etc/resolv.conf`, `/etc/nsswitch.conf`, the `HOSTALIASES` file, and if using a c-ares version prior to 1.27.0, the `/etc/hosts` file. If any of these configuration files has an embedded `NULL` character as the first character in a new line, it can lead to attempting to read memory prior to the start of the given buffer which may result in a crash. This issue is fixed in c-ares 1.27.0. No known workarounds exist.

Affected products

• C-Ares C-Ares: before 1.27.0 (fixed in 1.27.0)
• Fedoraproject Fedora: version 38 only; version 39 only; version 40 only

Published 2024-02-23. Last modified 2026-06-17.