PHP 4.0.0 through 4.4.6 and 5.0.0 through 5.2.1 allows context-dependent attackers to read arbitrary memory locations via an interruption that triggers a user space error handler that changes a parameter to an arbitrary pointer, as demonstrated via the iptcembed function, which calls certain convert_to_* functions with its input parameters.

PHP 5.2.1 allows context-dependent attackers to read portions of heap memory by executing certain scripts with a serialized data input string beginning with S:, which does not properly track the number of input bytes being processed.

The compress.bzip2:// URL wrapper provided by the bz2 extension in PHP before 4.4.7, and 5.x before 5.2.2, does not implement safemode or open_basedir checks, which allows remote attackers to read bzip2 archives located outside of the intended directories.