PHP2Shell: Failed Requests, Memory Corruption and Remote Code Execution

PHP2Shell affects how PHP handles a request that runs out of memory or encounters a fatal error. If the failure interrupts an operation before it finishes, PHP can leave an array entry only partly initialized or retain a pointer to memory that is later freed. Request cleanup or a subsequent request can then use that invalid state, causing memory corruption that can lead to remote code execution. Some exploitation paths run while PHP processes incoming form data, before the…