CVE-2007-1380 in PHP
Summary
by MITRE
The php_binary serialization handler in the session extension in PHP before 4.4.5, and 5.x before 5.2.1, allows context-dependent attackers to obtain sensitive information (memory contents) via a serialized variable entry with a large length value, which triggers a buffer over-read.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 08/25/2024
The vulnerability described in CVE-2007-1380 represents a critical buffer over-read flaw within PHP's session extension that existed in versions prior to 4.4.5 and 5.2.1. This issue specifically affects the php_binary serialization handler which processes session data when PHP applications use binary session serialization. The vulnerability arises from insufficient input validation during the deserialization process of session variables, creating a scenario where maliciously crafted session data can trigger memory access violations. Attackers can exploit this weakness by crafting serialized variable entries with excessively large length values that exceed the allocated buffer boundaries, causing the application to read beyond intended memory limits and potentially expose sensitive information from adjacent memory regions.
The technical implementation of this vulnerability stems from improper bounds checking within PHP's session handling code when processing binary serialized data. During the deserialization process, the system attempts to read a specified number of bytes based on a length field within the serialized data structure. When this length value is manipulated to exceed the actual buffer size, the system continues reading memory beyond its intended boundaries. This behavior creates a predictable pattern where attackers can control the amount of data read and potentially extract arbitrary memory contents including session tokens, database credentials, application secrets, or other sensitive information stored in adjacent memory locations. The vulnerability operates at the level of the PHP runtime environment and affects all applications that utilize PHP sessions with binary serialization, making it particularly dangerous in web applications where session management is fundamental.
The operational impact of CVE-2007-1380 extends beyond simple information disclosure to potentially enable more sophisticated attacks. While the primary risk involves memory content exposure, this vulnerability can serve as a stepping stone for attackers to gather intelligence about the target system's memory layout and application state. The extracted information could include session identifiers that allow session hijacking attacks, database connection details, or cryptographic keys that compromise application security. Additionally, the vulnerability may be leveraged in combination with other exploits to facilitate privilege escalation or remote code execution, particularly in environments where sensitive data is stored in predictable memory locations. This type of vulnerability aligns with CWE-125, which describes out-of-bounds read conditions, and demonstrates how improper input validation can create security weaknesses in serialization handlers.
Organizations affected by this vulnerability should immediately implement mitigations including upgrading to patched PHP versions where the buffer over-read issue has been resolved. The recommended approach involves updating PHP installations to versions 4.4.5 or 5.2.1 and later, which contain the necessary fixes to properly validate length fields during session deserialization. System administrators should also consider implementing additional security controls such as input sanitization for session data, monitoring for unusual session handling patterns, and regular security assessments of PHP applications. The vulnerability demonstrates the importance of proper memory management in language runtimes and highlights the need for comprehensive testing of serialization handlers against malformed input. Security teams should also review their incident response procedures to ensure preparedness for potential exploitation of similar buffer over-read vulnerabilities that may exist in other components of their PHP applications or underlying systems, as these flaws often represent entry points for broader exploitation campaigns.