PHP 4.4.4, 5.1.6, and other versions, when running on Apache, allows local users to modify behavior of other sites hosted on the same web server by modifying the mbstring.func_overload setting within .htaccess, which causes this setting to be applied to other virtual hosts on the same server.

References

• https://nvd.nist.gov/vuln/detail/CVE-2009-0754
• https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A11035
• https://usn.ubuntu.com/761-1/
• https://www.redhat.com/archives/fedora-package-announce/2009-May/msg01451.html
• https://www.redhat.com/archives/fedora-package-announce/2009-May/msg01465.html
• http://bugs.php.net/bug.php?id=27421
• http://lists.opensuse.org/opensuse-security-announce/2009-04/msg00003.html
• http://secunia.com/advisories/34642
• http://secunia.com/advisories/34830
• http://secunia.com/advisories/35003
• http://secunia.com/advisories/35007
• http://secunia.com/advisories/35306
• http://www.debian.org/security/2009/dsa-1789
• http://www.openwall.com/lists/oss-security/2009/01/30/1
• http://www.openwall.com/lists/oss-security/2009/02/03/3
• http://www.openwall.com/lists/oss-security/2009/02/25/3
• http://www.redhat.com/support/errata/RHSA-2009-0350.html
• http://www.securitytracker.com/id?1021979