CVE-2007-1649

CVE-2007-1649 describes a heap memory information leak vulnerability in PHP 5.2.1. Attackers can exploit this by providing a specially crafted serialized data input string beginning with "S:" to certain scripts, leading to the disclosure of portions of heap memory. This vulnerability has a high severity CVSS score of 7.8, indicating it is easily exploitable over the network with no authentication required, and can lead to complete confidentiality compromise. While not listed on the KEV catalog, an ExploitDB entry exists for a local information leak, and there is no evidence of widespread active exploitation or significant community discussion.