CVE-2014-4698 in PHP
Summary
by MITRE • 01/25/2023
Use-after-free vulnerability in ext/spl/spl_array.c in the SPL component in PHP through 5.5.14 allows context-dependent attackers to cause a denial of service or possibly have unspecified other impact via crafted ArrayIterator usage within applications in certain web-hosting environments.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 01/25/2023
The CVE-2014-4698 vulnerability represents a critical use-after-free flaw within PHP's Standard PHP Library component, specifically in the ext/spl/spl_array.c file. This vulnerability affects PHP versions through 5.5.14 and exploits a fundamental memory management error that occurs when ArrayIterator objects are manipulated within web hosting environments. The issue arises from improper handling of object references and memory deallocation processes, creating a scenario where freed memory can be accessed again by subsequent operations.
The technical implementation of this vulnerability stems from the SPL component's array handling mechanisms, where the ArrayIterator class fails to properly manage object lifecycle during garbage collection processes. When applications utilize ArrayIterator objects in specific patterns within web hosting contexts, the underlying memory management system can prematurely free object resources while references to those resources still exist. This creates a use-after-free condition that can be exploited by context-dependent attackers who craft malicious ArrayIterator usage patterns. The vulnerability is particularly dangerous because it can be triggered through normal application operation rather than requiring special privileges or complex exploitation techniques.
The operational impact of CVE-2014-4698 extends beyond simple denial of service scenarios to potentially enable more severe consequences including arbitrary code execution or system compromise. In web hosting environments where PHP applications process untrusted input, attackers can leverage this vulnerability to cause unpredictable behavior in the PHP interpreter. The vulnerability's context-dependent nature means that exploitation success relies on specific hosting configurations and application usage patterns, making it particularly insidious as it can be triggered through legitimate application functionality. This characteristic aligns with CWE-416, which describes the use of freed memory condition, and represents a classic memory safety issue that has been a persistent problem in C-based applications.
The exploitation of this vulnerability typically requires attackers to understand specific PHP application patterns and hosting configurations to craft effective payloads. Web hosting environments often provide the perfect conditions for exploitation due to their multi-tenant nature and the variety of PHP applications that may be running simultaneously. The vulnerability can be particularly dangerous in shared hosting environments where one compromised application could potentially affect other applications running on the same server. Mitigation strategies should focus on immediate PHP version updates to patched releases, implementation of proper input validation, and monitoring for unusual memory allocation patterns. Organizations should also consider implementing application-level protections such as PHP configuration hardening and regular security assessments. This vulnerability exemplifies the importance of proper memory management in interpreted languages and demonstrates how seemingly minor implementation flaws can create significant security risks in production environments. The issue highlights the need for comprehensive security testing of core library components and emphasizes the critical role of timely patch management in maintaining system integrity.