CVE-2007-1375 in PHP
Summary
by MITRE
Integer overflow in the substr_compare function in PHP 5.2.1 and earlier allows context-dependent attackers to read sensitive memory via a large value in the length argument, a different vulnerability than CVE-2006-1991.
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Analysis
by VulDB Data Team • 08/26/2024
The vulnerability identified as CVE-2007-1375 represents a critical integer overflow flaw within PHP's substr_compare function affecting versions 5.2.1 and earlier. This vulnerability operates through a context-dependent attack vector where malicious actors can manipulate the length argument to cause unexpected behavior in memory handling. The issue stems from insufficient input validation and integer overflow protection within the function's implementation, creating a potential pathway for unauthorized memory access.
The technical implementation of this vulnerability occurs when the substr_compare function processes a large length argument that exceeds the maximum value representable by the integer data type used in the function's internal calculations. This overflow condition causes the function to interpret the large value as a negative integer or wrap around to a small positive value, resulting in improper memory access patterns. The flaw specifically affects how PHP handles the length parameter in string comparison operations, where the function attempts to read memory beyond the intended boundaries of the target string.
From an operational perspective, this vulnerability poses significant security risks to web applications running vulnerable PHP versions. Attackers can exploit this weakness to potentially read sensitive data from memory locations that should remain protected, including session information, database credentials, or other confidential application data. The impact extends beyond simple information disclosure to potentially enable more sophisticated attacks such as code execution or privilege escalation depending on the application's memory layout and the specific data accessed. The vulnerability's classification aligns with CWE-190, which specifically addresses integer overflow conditions that can lead to memory corruption and unauthorized data access.
The exploitability of CVE-2007-1375 requires that an attacker can influence the length argument passed to substr_compare function calls within the application. This typically occurs when user input directly affects the function parameters, making it particularly dangerous in web applications that process untrusted data. The vulnerability demonstrates characteristics consistent with ATT&CK technique T1059, where adversaries leverage application-specific functions to access unintended system resources. Security professionals should note that this vulnerability operates independently from CVE-2006-1991, indicating a distinct implementation flaw within the PHP codebase.
Mitigation strategies for this vulnerability primarily involve immediate patching of affected PHP installations to versions that address the integer overflow condition. Organizations should implement comprehensive input validation and sanitization measures to prevent malicious length values from reaching the substr_compare function. Additionally, application-level protections such as proper error handling, memory access controls, and regular security assessments can help reduce the attack surface. System administrators should also consider implementing web application firewalls and monitoring solutions to detect potential exploitation attempts targeting this specific vulnerability. The remediation process should include thorough testing of patched applications to ensure compatibility and prevent regression issues while maintaining overall system security posture.