This release focuses on improving the stability ofthe PHP 5.2.x branch with over 120 bug fixes, several of which are security related.All users of PHP are encouraged to upgrade to this release. Further details about the PHP 5.2.6 release can be found in the release announcement for 5.2.6, the full list of changes is available in the ChangeLog for PHP 5.

Security updates include prevention of a buffer overflow in FastCGI mode, an integer overflow in printf, correction for a safe_mode bypass method in cURL and the bundling of PCRE 7.6 to update the regular expression functionality of the language.

You can grab this latest release from the downloads page on PHP.net (or your favorite mirror) - both the source and the Windows binaries.

The exploit has been published as a PHP file for easy testing on your Windows/PHP installation (it was tested on WinXP Pro SP2 on both the CLI and Apache). No additional modules are needed for this exploit - only the COM functions and a Windows system.

The issue comes from an overflow in the str_repeat function allowing for the execution of whatever applications the developer wants on the remote Windows machine (including the ability to create and remove files and directories). There is no path for this issue currently (should be corrected in the next minor PHP release).

This [bugfix] fixes the chunk_split() overflow (found by SEC-CONSULT) that was according to the PHP 5.2.3 release notes already fixed. The original fix was however not only broken but complete nonsense. If you can read C you will see that the integer overflow was not fixed in PHP 5.2.3 but simply moved into a separate line and an additional bogus if clause was added.

Stefan includes a simple four line code example to illustrate his point.

A weakness and a vulnerability have been reported in PHP 5, where the vulnerability has unknown impact and the weakness can be exploited by malicious, local users to bypass certain security restrictions.

The issue is caused by issues with the chunk_split and realpath functions that can lead to a bypass of the open_basedir restriction on a server.

The issue is marked as "moderately critical" and it is suggested that users update to PHP 5.2.3 to correct the issue.

When a PHP application is run in PHP 4 it can overflow the variable reference counter because it is only 16 bit wide. Whenever this happens it will result in a double destruction of the underlying variable. A local attacker can easily create PHP code that uses such a double destruction to execute arbitrary code within the process executing PHP (e.g. webserver process). This allows bypassing restrictions enforced by disable_functions, open_basedir, SAFE_MODE or to launch direct local root exploits against the target system.

The patch [tar.gz] fixes the issue and keeps from breaking anything from the past (backwards compatibility). You can either grab it now and apply it to your distribution (the sooner the better) or wait until it gets merged into the PHP CVS version and released with the next bug fix release.

The vulnerabilities are caused due to boundary errors within the "htmlentities()" and "htmlspecialchars()" functions. If a PHP application uses these functions to process user-supplied input, this can be exploited to cause a heap-based buffer overflow by passing specially crafted data to the affected application.

Successful exploitation may allow execution of arbitrary code, but requires that the UTF-8 character set is selected.

Products affected include the Network Analysis Modules (NAM) for Cisco 6500 switch, Cisco 7600 router/Branch Routers and the CiscoWorks Wireless LAN Solution Engine (WLSE) and CiscoWorks Wireless LAN Solution (among others, check out the advisory for a more complete list).

There are some patches that have been released to correct this issue (like the one for the Cisco Unified Application Environment) but others are still yet to come. They recommend limiting access to only trusted IPs and devices only to reduce the risk of the problem being exploited.

While we were searching for a hole in htmlspecialchars() and htmlentities() to bypass the encoding of certain chars to exploit a possible eval() injection hole in another application we discovered that the implementation contains a possible bufferoverflow that can be triggered when the UTF-8 charset is selected.

The issue has been corrected in the latest PHP 5 release - version 5.2 - but is still present in the PHP 4.4 series (they have a recommended patch until the new version is posted). You can get complete information about this issue from the full vulnerability listing.

The PHP 5 branch of the PHP source code lacks the protection against possible integer overflows inside ecalloc() that is present in the PHP 4 branch and also for several years part of our Hardening-Patch and our new Suhosin-Patch.

It was discovered that such an integer overflow can be triggered when user input is passed to the unserialize() function.

You can get the full details from this advisory release including a recommendation to patch the installation until it is corrected in the current distribution.

I've spent a lot of time with ODBC recently, working on interfacing our PostalEngine product with SQL Server. One of the things that caused me a LOT of trouble is binding date/time values into our stored procedure calls. One of the reasons that it was hard work was lack of documentation-by-example.

When this [code] is run, the execute fails with SQLSTATE 22008, Date time overflow. Everything looks correct in the code, and most of the values we're passing are based on the description of the parameter provided by ODBC, so what's going on?

After "several hours", he figures it out, the problem being a result of the precision field. He also includes an example of the "magic number" to put in their field to get things to parse correctly...]]> Fri, 25 Nov 2005 06:44:58 -0600