The (1) session_save_path, (2) ini_set, and (3) error_log functions in PHP 4.4.7 and earlier, and PHP 5 5.2.3 and earlier, when invoked from a .htaccess file, allow remote attackers to bypass safe_mode and open_basedir restrictions and possibly execute arbitrary commands, as demonstrated using (a) php_value, (b) php_flag, and (c) directives in .htaccess.
Multiple buffer overflows in libtidy, as used in the Tidy extension for PHP 5.2.3 and possibly other products, allow context-dependent attackers to execute arbitrary code via (1) a long second argument to the tidy_parse_string function or (2) an unspecified vector to the tidy_repair_string function. NOTE: this might only be an issue in environments where vsnprintf is implemented as a wrapper for vsprintf.
The parse_str function in (1) PHP, (2) Hardened-PHP, and (3) Suhosin, when called without a second parameter, might allow remote attackers to overwrite arbitrary variables by specifying variable names and values in the string to be parsed. NOTE: it is not clear whether this is a design limitation of the function or a bug in PHP, although it is likely to be regarded as a bug in Hardened-PHP and Suhosin.
The resource system in PHP 5.0.0 through 5.2.1 allows context-dependent attackers to execute arbitrary code by interrupting the hash_update_file function via a userspace (1) error or (2) stream handler, which can then be used to destroy and modify internal resources. NOTE: it was later reported that PHP 5.2 through 5.2.13 and 5.3 through 5.3.2 are also affected.
Buffer overflow in the snmpget function in the snmp extension in PHP 5.2.3 and earlier, including PHP 4.4.6 and probably other PHP 4 versions, allows context-dependent attackers to execute arbitrary code via a long value in the third argument (object id).