Vulnerability Note VU#943633
FreeBSD can be compromised locally via signal handlers
The FreeBSD operating system does not adequately clear signal handlers subsequent to a process calling exec() on a setuid program. This vulnerability can allow a local attacker to execute arbitrary code as root.
The unix fork() function's purpose is to create a new process from an existing process. The new process is called the child process, and the existing process is called the parent. When a process forks, it inherits the parent's signal handling settings. The unix exec() function's purpose is to replace the current process image with a new process image. After this has occured, the kernel should clear the signal handlers because they are no longer valid. Because the FreeBSD operating system does not adequately clear signal handlers subsequent to a process calling exec(), an attacker can execute arbitrary code as root.
An local attacker may be able to execute arbitrary code as root.
Apply a patch from your vendor or upgrade your operating system to FreeBSD 4.3-STABLE.
Systems Affected (Learn More)
|Vendor||Status||Date Notified||Date Updated|
|FreeBSD||Affected||02 Jul 2001||14 Sep 2001|
|Cray Inc.||Not Affected||-||04 Oct 2001|
|Hewlett-Packard Company||Not Affected||14 Sep 2001||21 Sep 2001|
CVSS Metrics (Learn More)
The CERT Coordination Center thanks Georgi Guninski for discovering this vulnerability and the FreeBSD project for providing a patch to address the vulnerability.
This document was written by Ian A. Finlay.
- CVE IDs: CVE-2001-1180
- Date Public: 10 Jul 2001
- Date First Published: 14 Sep 2001
- Date Last Updated: 12 Dec 2002
- Severity Metric: 29.25
- Document Revision: 30
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