Description of problem:
The session extension in PHP 4 before 4.4.5, and PHP 5 before 5.2.1, calculates
the reference count for the session variables without considering the internal
pointer from the session globals, which allows context-dependent attackers to
execute arbitrary code via a crafted string in the session_register after
unsetting HTTP_SESSION_VARS and _SESSION, which destroys the session data Hashtable.
The PHP interpreter does not offer a reliable "sandboxed" security layer (as
found in, say, a JVM) in which untrusted scripts can be run; any script run by
the PHP interpreter must be trusted with the privileges of the interpreter itself.
The bug described in CVE-2007-1700 can only be triggered by a script author;
since no trust boundary is crossed, this issue is not treated as security-sensitive.
*** Bug 239321 has been marked as a duplicate of this bug. ***