Multiple vulnerabilities in PHP.
It was discovered that PHP computed hash values for form parameters without restricting the ability to trigger hash collisions predictably. This could allow a remote attacker to cause a denial of service by sending many crafted parameters. (CVE-2011-4885)
10 February 2012
A security issue affects these releases of Ubuntu and its derivatives:
Multiple vulnerabilities in PHP.
It was discovered that PHP computed hash values for form parameters without restricting the ability to trigger hash collisions predictably. This could allow a remote attacker to cause a denial of service by sending many crafted parameters. (CVE-2011-4885)
ATTENTION: this update changes previous PHP behavior by limiting the number of external input variables to 1000. This may be increased by adding a “max_input_vars” directive to the php.ini configuration file. See http://www.php.net/manual/en/info.configuration.php#ini.max-input-vars for more information.
Stefan Esser discovered that the fix to address the predictable hash collision issue, CVE-2011-4885, did not properly handle the situation where the limit was reached. This could allow a remote attacker to cause a denial of service or execute arbitrary code via a request containing a large number of variables. (CVE-2012-0830)
It was discovered that PHP did not always check the return value of the zend_strndup function. This could allow a remote attacker to cause a denial of service. (CVE-2011-4153)
It was discovered that PHP did not properly enforce libxslt security settings. This could allow a remote attacker to create arbitrary files via a crafted XSLT stylesheet that uses the libxslt output extension. (CVE-2012-0057)
It was discovered that PHP did not properly enforce that PDORow objects could not be serialized and not be saved in a session. A remote attacker could use this to cause a denial of service via an application crash. (CVE-2012-0788)
It was discovered that PHP allowed the magic_quotes_gpc setting to be disabled remotely. This could allow a remote attacker to bypass restrictions that could prevent an SQL injection. (CVE-2012-0831)
USN 1126-1 addressed an issue where the /etc/cron.d/php5 cron job for PHP allowed local users to delete arbitrary files via a symlink attack on a directory under /var/lib/php5/. Emese Revfy discovered that the fix had not been applied to PHP for Ubuntu 10.04 LTS. This update corrects the issue. We apologize for the error. (CVE-2011-0441)
The problem can be corrected by updating your system to the following package versions:
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
In general, a standard system update will make all the necessary changes.
Vulmon