PHP is an HTML-embedded scripting language commonly used with the ApacheHTTP Server.It was found that the hashing routine used by PHP arrays was susceptibleto predictable hash collisions. If an HTTP POST request to a PHPapplication contained many parameters whose names map to the same hashvalue, a large amount of CPU time would be consumed. This flaw has beenmitigated by adding a new configuration directive, max_input_vars, thatlimits the maximum number of parameters processed per request. Bydefault, max_input_vars is set to 1000. (CVE-2011-4885)A use-after-free flaw was found in the PHP substr_replace() function. If aPHP script used the same variable as multiple function arguments, a remoteattacker could possibly use this to crash the PHP interpreter or, possibly,execute arbitrary code. (CVE-2011-1148)An integer overflow flaw was found in the PHP exif extension. On 32-bitsystems, a specially-crafted image file could cause the PHP interpreter tocrash or disclose portions of its memory when a PHP script tries to extractExchangeable image file format (Exif) metadata from the image file.(CVE-2011-4566)An insufficient input validation flaw, leading to a buffer over-read, wasfound in the PHP exif extension. A specially-crafted image file could causethe PHP interpreter to crash when a PHP script tries to extractExchangeable image file format (Exif) metadata from the image file.(CVE-2011-0708)An integer overflow flaw was found in the PHP calendar extension. A remoteattacker able to make a PHP script call SdnToJulian() with a large valuecould cause the PHP interpreter to crash. (CVE-2011-1466)A bug in the PHP Streams component caused the PHP interpreter to crash ifan FTP wrapper connection was made through an HTTP proxy. A remote attackercould possibly trigger this issue if a PHP script accepted an untrusted URLto connect to. (CVE-2011-1469)An off-by-one flaw was found in PHP. If an attacker uploaded a file with aspecially-crafted file name it could cause a PHP script to attempt to writea file to the root (/) directory. By default, PHP runs as the "apache"user, preventing it from writing to the root directory. (CVE-2011-2202)Red Hat would like to thank oCERT for reporting CVE-2011-4885. oCERTacknowledges Julian Wälde and Alexander Klink as the original reporters ofCVE-2011-4885.All php users should upgrade to these updated packages, which containbackported patches to resolve these issues. After installing the updatedpackages, the httpd daemon must be restarted for the update to take effect.