search menu icon-carat-right cmu-wordmark

CERT Coordination Center

HPUX kmmodreg allows arbitrary file overwriting via symlink redirection of temporary file

Vulnerability Note VU#127435

Original Release Date: 2001-07-31 | Last Revised: 2001-08-01

Overview

The kmmodreg program distributed with some HPUX versions creates two temporary files with predictable names. Due to insecure handling of these files, an intruder may use them to overwrite arbitrary files during system boot via a symbolic link attack.

Description

The kmmodreg program distributed with some HPUX versions creates two files in /tmp: /tmp.kmmodreg_lock and /tmp/kmpath.tmp. The creat() call used in this program does not check for prior existence of either file.

Impact

By creating symbolic links named for either of the two temporary files, an intruder can overwrite any file in the system with data from kmmodreg. Since kmmodreg runs automatically during reboot, no separate invocation is required. The overwrite may cause a file corruption leading to denial of service, or, since the temporary files are created to allow modification by anyone (protected 666), this may be used to allow modification of system files leading to increased user privileges.

Solution

Apply vendor patches; see the Systems Affected section below.

Vendor Information

127435
 

CVSS Metrics

Group Score Vector
Base
Temporal
Environmental

References

Acknowledgements

This vulnerability was first reported by Graf Potozky.

This document was last updated by Tim Shimeall.

Other Information

CVE IDs: CVE-2001-1256
Severity Metric: 11.64
Date Public: 2001-06-04
Date First Published: 2001-07-31
Date Last Updated: 2001-08-01 16:17 UTC
Document Revision: 6

Sponsored by CISA.