USN-99-1: PHP4 vulnerabilities

18 March 2005

php4 vulnerabilities

A security issue affects these releases of Ubuntu and its derivatives:

  • Ubuntu 4.10

Software Description


Stefano Di Paola discovered integer overflows in PHP’s pack() and unpack() functions. A malicious PHP script could exploit these to break out of safe mode and execute arbitrary code with the privileges of the PHP interpreter. (CAN-2004-1018)

Note: The second part of CAN-2004-1018 (buffer overflow in the shmop_write() function) was already fixed in USN-66-1.

Stefan Esser discovered two safe mode bypasses which allowed malicious PHP scripts to circumvent path restrictions. This was possible by either using virtual_popen() with a current directory containing shell metacharacters (CAN-2004-1063) or creating a specially crafted directory whose length exceeded the capacity of the realpath() function (CAN-2004-1064).

Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 4.10

To update your system, please follow these instructions: