Apple Mac OS X cs_validate_page function denial of service

macosx-csvalidatepage-dos (38997) The risk level is classified as LowLow Risk

Description:

Apple Mac OS X is vulnerable to a denial of service attack, caused by improper bounds checking of user-supplied input by the cs_validate_page function in the bsd/kern/ubc_subr.c file. A local attacker could exploit this vulnerability by causing the hashes function to return a NULL value, resulting in a kernel panic.

Platforms Affected:

  • Apple, Mac OS X 10.5
  • Apple, Mac OS X 10.5.1
  • Apple, Mac OS X 10.5.2
  • Apple, Mac OS X Server 10.5
  • Apple, Mac OS X Server 10.5.1
  • Apple, Mac OS X Server 10.5.2

Remedy:

Apply Security Update 2008-003, available from the Apple Web site. See References.

Consequences:

Denial of Service

References:

  • Apple Web site, Apple at http://www.apple.com/.
  • Apple Web site, About the security content of Security Update 2008-003 / Mac OS X 10.5.3 at http://support.apple.com/kb/HT1897.
  • digit-labs Web site, Apple Mac OS X xnu <= 1228.0 cs_validate_page Local Kernel Denial of Service at http://digit-labs.org/files/exploits/xnu-superblob-dos.c.
  • BID-26840: Apple Mac OS X ubc_subr.c Local Denial of Service Vulnerability
  • CVE-2007-6359: The cs_validate_page function in bsd/kern/ubc_subr.c in the xnu kernel 1228.0 and earlier in Apple Mac OS X 10.5.1 allows local users to cause a denial of service (failed assertion and system crash) via a crafted signed Mach-O binary that causes the hashes function to return NULL.
  • FrSIRT/ADV-2007-4216: Apple Mac OS X cs_validate_page Local Denial of Service Vulnerability
  • FrSIRT/ADV-2008-1697: Apple Mac OS X Command Execution and Security Bypass Issues
  • SA28048: Mac OS X "cs_validate_page()" Local Denial of Service
  • SA30430: Apple Mac OS X Security Update Fixes Multiple Vulnerabilities

Reported:

Dec 12, 2007

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