The proxy server feature in go-pear.php in PHP PEAR 0.2.2, as used in Apache2Triad, allows remote attackers to execute arbitrary PHP code by redirecting go-pear.php to a malicious proxy server that provides a modified version of Tar.php with a malicious extractModify function.
Improper Control of Generation of Code The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.