(RHSA-2004:392) php security update

PHP is an HTML-embedded scripting language commonly used with the Apache
HTTP server.

Stefan Esser discovered a flaw when memory_limit is enabled in versions of
PHP 4 before 4.3.8. If a remote attacker could force the PHP interpreter to
allocate more memory than the memory_limit setting before script execution
begins, then the attacker may be able to supply the contents of a PHP hash
table remotely. This hash table could then be used to execute arbitrary
code as the ‘apache’ user. The Common Vulnerabilities and Exposures project
(cve.mitre.org) has assigned the name CAN-2004-0594 to this issue.

This issue has a higher risk when PHP is running on an instance of Apache
which is vulnerable to CAN-2004-0493. For Red Hat Enterprise Linux 3, this
Apache memory exhaustion issue was fixed by a previous update,
RHSA-2004:342. It may also be possible to exploit this issue if using a
non-default PHP configuration with the “register_defaults” setting is
changed to “On”. Red Hat does not believe that this flaw is exploitable in
the default configuration of Red Hat Enterprise Linux 3.

Stefan Esser discovered a flaw in the strip_tags function in versions of
PHP before 4.3.8. The strip_tags function is commonly used by PHP scripts
to prevent Cross-Site-Scripting attacks by removing HTML tags from
user-supplied form data. By embedding NUL bytes into form data, HTML tags
can in some cases be passed intact through the strip_tags function, which
may allow a Cross-Site-Scripting attack. The Common Vulnerabilities and
Exposures project (cve.mitre.org) has assigned the name CAN-2004-0595 to
this issue.

All users of PHP are advised to upgrade to these updated packages, which
contain backported patches that address these issues.