Vulnerability Note VU#426456

gpm creates temporary files insecurely

Original Release date: 08 Jun 2001 | Last revised: 22 Jun 2001

Overview

gpm version 1.19.3, which usually runs as root, is vulnerable due to a flaw that allows a local user to exploit a race condition to corrupt files that gpm uses.

Description

gpm (General Purpose Mouse) is a program that lets you use the mouse in console mode when not using XWindows. It is usually included in Linux distributions, and can be started from the command line or in the startup script /etc/rc.d/rc.local. A vulnerability in gpm version 1.19.3 allows a local user to exploit a race condition to corrupt files that gpm uses. The flaw exists because gpm creates files in the /tmp directory using predictable filenames without checking whether a file with that name already exists. Malicious local users can therefore create a symbolic link to a file that will be used by gpm. When gpm is run, the creation of the file fails (since it already exists) and gpm uses the symbolically linked file for its processing. The malicious user can then overwrite or append to the file as it is being used by the privileged gpm program.

Impact

Malicious users can destroy the integrity of or deny access to files processed by gpm, which usually runs as root.

Solution

Upgrade affected Linux distributions.

Systems Affected (Learn More)

VendorStatusDate NotifiedDate Updated
ImmunixAffected10 Jan 200101 Jun 2001
MandrakeSoftAffected12 Jan 200101 Jun 2001
RedHatAffected10 Jan 200101 Jun 2001
If you are a vendor and your product is affected, let us know.

CVSS Metrics (Learn More)

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

References

Credit

Thanks to Greg Kroah-Hartman of WireX for discovering this vulnerability. Thanks also to BugTraq for a good description of the underlying problem.

This document was written by Andy Moore.

Other Information

  • CVE IDs: CVE-2001-0116
  • Date Public: 10 Jan 2001
  • Date First Published: 08 Jun 2001
  • Date Last Updated: 22 Jun 2001
  • Severity Metric: 2.66
  • Document Revision: 13

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