FreeBSD i386_set_ldt Integer Overflow Vulnerability
iDefense Security Advisory 09.23.06 http://www.idefense.com/intelligence/vulnerabilities/ Sep 23, 2006
FreeBSD is a modern operating system for x86, amd64, Alpha, IA-64, PC-98 and SPARC architectures. It's based on the UNIX operating system, BSD, which was created at the University of California, Berkeley. More information can be obtained from the FreeBSD Project web site at http://www.FreeBSD.org/
Local exploitation of a input validation error in the FreeBSD Project's i386_set_ldt() kernel implementation could allow attackers to create a kernel panic, leading to a denial of service condition on the affected computer.
Exploitation of this vulnerability would result in a denial of service condition on the affected host. There is a potential for arbitrary code execution in kernel context due to the way this function manipulates kernel heap memory.
iDefense has confirmed the existence of this problem in FreeBSD 5.5. It is suspected that versions as early as 5.2 are also affected.
iDefense is not aware of any workaround for this issue.
VI. VENDOR RESPONSE
"It appears that the problem you have discovered was fixed in revision 1.96 of src/sys/i386/i386/sys_machdep.c on March 23, 2005, after being found by the Coverity Prevent analysis tool; the commit message at the time documented this as a local denial of service bug.
The policy of the FreeBSD Security Team is that local denial of service bugs not be treated as security issues; it is possible that this problem will be corrected in a future Erratum."
VII. CVE INFORMATION
The Common Vulnerabilities and Exposures (CVE) project has assigned the name CVE-2006-4172 to this issue. This is a candidate for inclusion in the CVE list (http://cve.mitre.org), which standardizes names for security problems.
VIII. DISCLOSURE TIMELINE
08/16/2006 Initial vendor notification 08/16/2006 Initial vendor response 09/23/2006 Public disclosure
The discoverer of this vulnerability wishes to remain anonymous.
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X. LEGAL NOTICES
Copyright © 2006 iDefense, Inc.
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