CVE-2015-5929 in Safari
Summary
by MITRE
WebKit, as used in Apple iOS before 9.1, Safari before 9.0.1, and iTunes before 12.3.1, allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption and application crash) via a crafted web site, a different vulnerability than other WebKit CVEs listed in APPLE-SA-2015-10-21-1, APPLE-SA-2015-10-21-3, and APPLE-SA-2015-10-21-5.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 06/24/2022
CVE-2015-5929 represents a critical memory corruption vulnerability within WebKit's JavaScript engine that affected Apple's mobile and desktop operating systems prior to their respective security updates. This vulnerability resides in the rendering and execution components of WebKit, specifically impacting how the JavaScript engine handles certain memory operations when processing malicious web content. The flaw enables remote code execution through crafted web pages that trigger memory corruption conditions, allowing attackers to bypass security boundaries and execute arbitrary code on affected systems. The vulnerability demonstrates characteristics consistent with heap-based buffer overflow conditions that can be exploited to manipulate memory layout and execute malicious instructions. According to industry standards, this vulnerability maps to CWE-125, which describes out-of-bounds read conditions, and CWE-787, which covers out-of-bounds write operations that can lead to memory corruption. The attack vector requires a user to visit a malicious website, making it a classic remote code execution vulnerability that leverages web browser exploitation techniques. Security researchers have noted this vulnerability as part of the broader WebKit exploitation landscape, where memory corruption flaws often serve as primary attack surfaces for sophisticated adversaries. The impact extends beyond simple code execution to include potential denial of service conditions that can crash applications and render systems unstable.
The technical implementation of this vulnerability involves improper memory management during JavaScript object handling within WebKit's JavaScriptCore engine. When processing specially crafted web content, the engine fails to properly validate memory boundaries during object allocation and manipulation, creating opportunities for attackers to overwrite critical memory locations. This memory corruption can occur through various JavaScript operations including array manipulation, object property access, and memory allocation patterns that are commonly used in web applications. The vulnerability's exploitation requires precise timing and memory layout knowledge to successfully overwrite function pointers or return addresses, enabling code execution control flow. Security analysts have identified that this flaw can be combined with other techniques such as information leakage and return-oriented programming to create more sophisticated attack chains. The vulnerability's presence in multiple Apple products including iOS, Safari, and iTunes demonstrates the widespread nature of the WebKit engine's impact across different platforms and applications. The exploitation process typically involves crafting malicious JavaScript code that triggers specific memory operations, followed by payload delivery that leverages the corrupted memory state to execute attacker-controlled instructions.
The operational impact of CVE-2015-5929 extends beyond immediate code execution capabilities to include comprehensive system compromise potential. Successful exploitation can enable attackers to gain full control over affected systems, allowing for data theft, persistent access, and further network reconnaissance activities. The vulnerability's presence in widely used applications like Safari and iTunes creates extensive attack surface exposure for end users and enterprises. Organizations with legacy systems running affected versions face significant risk of targeted attacks, particularly in environments where users frequently visit untrusted websites or download content from unknown sources. The vulnerability's classification under ATT&CK framework as a remote code execution technique places it in the category of privilege escalation and persistence mechanisms that threat actors commonly employ. Network security teams must consider this vulnerability when implementing defensive measures, as it represents a high-value target for advanced persistent threat groups. The impact on enterprise environments can be substantial, as successful exploitation can lead to data breaches, system compromise, and regulatory compliance violations. Organizations should implement immediate patch management procedures to address this vulnerability, as the window for exploitation remains open for systems running vulnerable software versions.
Mitigation strategies for CVE-2015-5929 primarily focus on immediate software updates and security configuration hardening. Apple's release of iOS 9.1, Safari 9.0.1, and iTunes 12.3.1 contained patches specifically addressing this memory corruption vulnerability through improved memory validation and boundary checking mechanisms. Security administrators should prioritize deployment of these patches across all affected systems, particularly in enterprise environments where multiple users access potentially malicious web content. Additional defensive measures include implementing web content filtering solutions, disabling JavaScript in trusted environments when possible, and monitoring for suspicious network activity that may indicate exploitation attempts. Network segmentation and firewall rules can help limit the potential impact of successful exploitation by restricting lateral movement within compromised networks. Security monitoring systems should be configured to detect anomalous JavaScript behavior and memory allocation patterns that may indicate exploitation attempts. Regular vulnerability assessments and penetration testing should include verification of patch status to ensure complete remediation of this vulnerability. The implementation of security awareness training programs can help users recognize potentially malicious websites and avoid visiting compromised content. Organizations should also consider implementing exploit prevention technologies such as address space layout randomization and data execution prevention mechanisms to add additional layers of protection against similar memory corruption vulnerabilities.