Sun Microsystems Solaris ACE_SETACL Integer Signedness DoS Vulnerability

iDefense Security Advisory 05.07.07
http://labs.idefense.com/intelligence/vulnerabilities/ 
May 07, 2007

I. BACKGROUND

Solaris is a UNIX operating system developed by Sun Microsystems. More
information can be found via the following URL.

http://www.sun.com/software/solaris/ 

II. DESCRIPTION

Local exploitation of an integer signedness error in Sun Microsystem's
Solaris could allow attackers to cause a kernel panic, leading to a DoS
condition on the affected computer.

The facl() system call is used to set access controls on a file. Due to
an improper check on one of the arguments passed to this function, an
attacker can cause the kernel allocate a large amount of memory which
causes a kernel panic.

III. ANALYSIS

Exploitation of this vulnerability would most likely result in a DoS
condition on the affected host. However, there are other functions
called by this function that use the result of the multiplication
performed to allocate memory. On a 64 bit kernel with several gigabytes
of RAM, code execution may be possible. Fixing this vulnerability will
also fix the later vulnerabilities.

IV. DETECTION

iDefense has confirmed the existence of this vulnerability in Solaris 10
on x86 and SPARC architectures. It is suspected that earlier versions
are also affected.

V. WORKAROUND

iDefense is currently unaware of any effective workarounds for this
issue.

VI. VENDOR RESPONSE

Sun Microsystems has addressed this vulnerability by releasing patches.
More information is available from Sun Alert ID 102869 at the following
URL.

http://sunsolve.sun.com/search/document.do?assetkey=1-26-102869-1 

VII. CVE INFORMATION

A Mitre Corp. Common Vulnerabilities and Exposures (CVE) number has not
been assigned yet.

VIII. DISCLOSURE TIMELINE

11/07/2006  Initial vendor notification
11/10/2006  Initial vendor response
05/07/2007  Coordinated public disclosure

IX. CREDIT

The discoverer of this vulnerability wishes to remain anonymous.

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X. LEGAL NOTICES

Copyright =A9 2007 iDefense, Inc.

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