SSH Secure Shell for Servers fails to remove child process from master process group

2002-11-25T00:00:00
ID VU:740619
Type cert
Reporter CERT
Modified 2008-05-29T00:00:00

Description

Overview

A locally exploitable privilege escalation vulnerability exists in SSH Secure Shell versions 2.0.13 - 3.2.1.

Description

Secure Shell for Servers, developed by SSH Communications Security, does not properly remove the child process from the master process group after non-interactive command execution. Quoting from the SSH Communications Security Advisory:

When used in non-interactive connections, a defect in process grouping
of SSH Secure Shell processes may allow malicious activity. If
executing a command without a pty (including running commands and
subsystems) the child process remains in the process group of the
master process.

On platforms relying on getlogin() (mainly the different BSD variants)
malicious users can at least send misleading messages to syslog and
others applications (getlogin() call will return "root").
For more details, please see the SSH Communications Security Advisory.


Impact

A local attacker may be able to gain elevated privileges.


Solution

Upgrade your software. Note that both Secure Shell for Servers and Secure Shell for Workstations need to be updated to eliminate this vulnerability.


Systems Affected

Vendor| Status| Date Notified| Date Updated
---|---|---|---
SSH Communications Security| | -| 14 May 2003
Hewlett-Packard Company| | -| 29 May 2008
If you are a vendor and your product is affected, let us know.

CVSS Metrics

Group | Score | Vector
---|---|---
Base | N/A | N/A
Temporal | N/A | N/A
Environmental | N/A | N/A

References

  • <http://www.ssh.com/company/newsroom/article/286/>

Credit

Thanks to Logan Gabriel for reporting this vulnerability.

This document was written by Ian A Finlay.

Other Information

  • CVE IDs: Unknown
  • Date Public: 25 Nov 2002
  • Date First Published: 25 Nov 2002
  • Date Last Updated: 29 May 2008
  • Severity Metric: 8.35
  • Document Revision: 15