CVE-2024-25629: c-ares Buffer Under-read

Vulnerability summary

CVE-2024-25629 is a medium (CVSS 5.5) Buffer Under-read vulnerability in c-ares. EPSS estimates a 0.35% chance of exploitation in the next 30 days, higher than 27.3% of scored vulnerabilities.

Timeline

1. 23-02-2024
   PublishedVulnerability first disclosed.
2. 13-02-2025
   Last modifiedVulnerability information updated.

Description

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.

• CWE-127Buffer Under-readThe product reads from a buffer using buffer access mechanisms such as indexes or pointers that reference memory locations prior to the targeted buffer.
• CWE-125Out-of-bounds ReadThe product reads data past the end, or before the beginning, of the intended buffer.