PHP posix_access() security bypass

php-posixaccess-security-bypass (43196) The risk level is classified as MediumMedium Risk

Description:

PHP could allow a remote attacker to bypass security restrictions, caused by an error in the posix_access() and possibly other functions. A remote attacker could exploit this vulnerability using a specially-crafted PHP script to bypass safe mode restrictions on a shared-server environment to access arbitrary files outside of the Web root and possibly launch further attacks against the system.

*CVSS:

Base Score: 2.6
  Access Vector: Network
  Access Complexity: High
  Authentication: None
  Confidentiality Impact: None
  Integrity Impact: Partial
  Availability Impact: None
 
Temporal Score: 1.9
  Exploitability: Unproven
  Remediation Level: Official-Fix
  Report Confidence: Confirmed

Consequences:

Bypass Security

Remedy:

For Apple Mac OS:
Apply Apple Security Update 2009-002, available from the Apple Web site. See References.

Upgrade to the latest version of PHP (5.2.7 or later), available from the PHP Web site. See References.

For other distributions:
Apply the appropriate update for your system. See References.

References:

  • Apple Web site: About the security content of Security Update 2009-002 / Mac OS X v10.5.7.
  • HPSBUX02431 SSRT090085 rev.1: HP-UX Running Apache Web Server Suite, Remote Denial of Service (DoS), Execution of Arbitrary Code.
  • PHP Web site: PHP: Hypertext Preprocessor.
  • PHP Web site: PHP 5 ChangeLog, Version 5.2.7.
  • SecurityReason Advisory: SecurityAlert : 54: PHP 5.2.6 posix_access() (posix ext) safe_mode bypass.
  • ASA-2009-255: HPSBUX02431 SSRT090085 rev.1 - HP-UX Running Apache Web Server SuiteRemote Denial of Service (DoS) Execution of Arbitrary Code
  • BID-29797: PHP 5 'posix_access()' Function 'safe_mode' Bypass Directory Traversal Vulnerability
  • CVE-2008-2665: Directory traversal vulnerability in the posix_access function in PHP 5.2.6 and earlier allows remote attackers to bypass safe_mode restrictions via a .. (dot dot) in an http URL, which results in the URL being canonicalized to a local filename after the safe_mode check has successfully run.
  • GLSA-200811-05: PHP: Multiple vulnerabilities
  • SA35074: Apple Mac OS X Security Update Fixes Multiple Vulnerabilities
  • SA35650: HP-UX Apache Web Server Suite Multiple Vulnerabilities
  • SECTRACK ID: 1020327: PHP posix_access() safe_mode Restrictions Can By Bypass With 'http://' Prefix
  • VUPEN/ADV-2009-1297: Apple Mac OS X Code Execution and Security Bypass Vulnerabilities

Platforms Affected:

  • Apache HTTP Server 2.0.59
  • Apache HTTP Server 2.2.8
  • Apache Tomcat 5.5.27
  • Apple Mac OS X 10.5
  • Apple Mac OS X 10.5.1
  • Apple Mac OS X 10.5.2
  • Apple Mac OS X 10.5.3
  • Apple Mac OS X 10.5.4
  • Apple Mac OS X 10.5.5
  • Apple Mac OS X 10.5.6
  • Apple Mac OS X Server 10.5
  • Apple Mac OS X Server 10.5.1
  • Apple Mac OS X Server 10.5.2
  • Apple Mac OS X Server 10.5.3
  • Apple Mac OS X Server 10.5.4
  • Apple Mac OS X Server 10.5.5
  • Apple Mac OS X Server 10.5.6
  • Gentoo Linux
  • HP HP-UX B.11.11
  • HP HP-UX B.11.23
  • HP HP-UX B.11.31
  • PHP PHP 5.2.6

Reported:

Jun 18, 2008

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The information within this database may change without notice. Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. In no event shall IBM be held liable for any damages whatsoever arising out of or in connection with the use or spread of this information.

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