CVE-2002-1396 in PHP
Summary
by MITRE
Heap-based buffer overflow in the wordwrap function in PHP after 4.1.2 and before 4.3.0 may allow attackers to cause a denial of service or execute arbitrary code.
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Analysis
by VulDB Data Team • 05/13/2019
The vulnerability identified as CVE-2002-1396 represents a critical heap-based buffer overflow within PHP's wordwrap function, affecting versions between 4.1.2 and 4.3.0. This flaw resides in the memory management implementation of the wordwrap function which processes text wrapping operations, creating a potential avenue for remote code execution or denial of service attacks. The issue stems from inadequate bounds checking during memory allocation for string processing operations, particularly when handling specially crafted input strings that exceed expected buffer boundaries.
The technical implementation of this vulnerability involves the wordwrap function's handling of character sequences and memory allocation patterns within PHP's runtime environment. When processing text that exceeds predetermined buffer limits, the function fails to properly validate input lengths before allocating heap memory, leading to memory corruption that can be exploited by malicious actors. This heap corruption occurs because the function does not perform adequate input validation or memory boundary checks, allowing attackers to overwrite adjacent memory locations with controlled data. The vulnerability specifically targets the heap memory management subsystem where PHP dynamically allocates memory for string operations, making it particularly dangerous as it can lead to arbitrary code execution through memory overwrite techniques.
The operational impact of CVE-2002-1396 extends beyond simple denial of service to encompass potential remote code execution capabilities that could compromise entire web servers running vulnerable PHP versions. Attackers exploiting this vulnerability could cause applications to crash or, more dangerously, inject and execute malicious code within the web server process context. The vulnerability affects web applications that utilize the wordwrap function for text processing, particularly those handling user input without proper sanitization, creating widespread exposure across PHP-based web environments. This makes it particularly dangerous in shared hosting environments or applications where user input flows directly into text processing functions.
The exploitation of this vulnerability aligns with attack patterns documented in the MITRE ATT&CK framework under the technique of code injection and privilege escalation, specifically targeting memory corruption vulnerabilities. The CWE (Common Weakness Enumeration) classification for this issue would fall under CWE-121, heap-based buffer overflow, which is a well-documented weakness in software security practices. Organizations running affected PHP versions face significant risk of unauthorized access and system compromise, particularly when applications process untrusted input through the wordwrap function. The vulnerability's impact is amplified by the widespread use of PHP in web applications and the ease with which attackers can craft malicious input to trigger the buffer overflow condition.
Mitigation strategies for CVE-2002-1396 require immediate patching of affected PHP installations to versions 4.3.0 or later where the vulnerability has been addressed through proper bounds checking and memory management improvements. System administrators should implement comprehensive input validation measures, particularly for any text processing functions that may be vulnerable to similar memory corruption issues. Network segmentation and application firewalls can provide additional protective layers while patches are deployed. Regular security assessments should include verification of PHP versions and implementation of secure coding practices to prevent similar vulnerabilities in custom applications. Organizations should also establish monitoring procedures to detect potential exploitation attempts and maintain updated security incident response protocols to address any successful attacks against vulnerable systems.