CVE-2014-3668 in PHP
Summary
by MITRE
Buffer overflow in the date_from_ISO8601 function in the mkgmtime implementation in libxmlrpc/xmlrpc.c in the XMLRPC extension in PHP before 5.4.34, 5.5.x before 5.5.18, and 5.6.x before 5.6.2 allows remote attackers to cause a denial of service (application crash) via (1) a crafted first argument to the xmlrpc_set_type function or (2) a crafted argument to the xmlrpc_decode function, related to an out-of-bounds read operation.
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Analysis
by VulDB Data Team • 02/23/2022
The vulnerability identified as CVE-2014-3668 represents a critical buffer overflow flaw within PHP's XMLRPC extension implementation. This issue specifically affects the date_from_ISO8601 function located in libxmlrpc/xmlrpc.c, which is part of the mkgmtime implementation. The vulnerability manifests when processing malformed XMLRPC data through two primary attack vectors: either a crafted first argument to the xmlrpc_set_type function or a malformed argument to the xmlrpc_decode function. The flaw enables remote attackers to trigger out-of-bounds read operations that ultimately result in application crashes and denial of service conditions. This vulnerability is particularly concerning as it affects multiple PHP version branches including 5.4.x, 5.5.x, and 5.6.x, indicating a widespread impact across the PHP ecosystem during that timeframe.
The technical exploitation of this vulnerability stems from improper bounds checking within the date parsing logic of the XMLRPC extension. When PHP processes XMLRPC requests containing malformed date strings, the date_from_ISO8601 function fails to validate input boundaries properly, leading to buffer overflow conditions. This type of vulnerability falls under CWE-121, which describes stack-based buffer overflow conditions, and also relates to CWE-125, indicating out-of-bounds read operations. The implementation flaw occurs in the mkgmtime function where date conversion logic does not adequately validate the length of input strings before attempting to parse them, creating opportunities for attackers to manipulate memory layout through carefully crafted input data.
The operational impact of CVE-2014-3668 extends beyond simple denial of service to potentially enabling more sophisticated attacks within vulnerable systems. When exploited successfully, the buffer overflow can cause the PHP application to crash, leading to service unavailability for legitimate users and potentially allowing attackers to execute arbitrary code under certain conditions. This vulnerability particularly affects web applications that rely heavily on XMLRPC functionality for data exchange, such as web services, API endpoints, and content management systems that utilize XMLRPC protocols for communication. The attack surface is broad as it affects any PHP application that processes XMLRPC data from untrusted sources, making it a significant concern for web infrastructure providers and application developers.
Mitigation strategies for CVE-2014-3668 primarily focus on immediate patching and implementation of input validation measures. Organizations should prioritize upgrading to PHP versions 5.4.34, 5.5.18, or 5.6.2, which contain the necessary fixes for this vulnerability. Additionally, implementing strict input validation for all XMLRPC data processing can serve as a temporary workaround while awaiting patch deployment. Network-level defenses should include monitoring for suspicious XMLRPC traffic patterns and implementing rate limiting to prevent exploitation attempts. From a security framework perspective, this vulnerability aligns with ATT&CK technique T1203, which covers exploitation of software vulnerabilities, and T1499, covering network disruption through service availability attacks. System administrators should also consider implementing intrusion detection systems that can identify and block malformed XMLRPC requests that attempt to exploit this buffer overflow condition.