CVE-2017-5129 in Chrome
Summary
by MITRE
A use after free in WebAudio in Blink in Google Chrome prior to 62.0.3202.62 allowed a remote attacker to perform an out of bounds memory read via a crafted HTML page.
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Analysis
by VulDB Data Team • 02/06/2023
The vulnerability identified as CVE-2017-5129 represents a critical use-after-free flaw within the WebAudio component of Blink, the rendering engine that powers Google Chrome. This issue arises from improper memory management during the handling of audio processing operations, creating a scenario where freed memory locations could be accessed by malicious code. The vulnerability specifically affects Chrome versions prior to 62.0.3202.62, making it a significant concern for users running outdated browser versions. The flaw manifests through a crafted HTML page that triggers the problematic code path, enabling remote exploitation without requiring any user interaction beyond visiting the malicious website.
The technical implementation of this vulnerability involves the WebAudio API's handling of audio buffer management within the Blink engine's JavaScript execution environment. When processing audio data through WebAudio nodes, the system allocates memory for audio buffers and subsequently frees this memory when no longer needed. However, a race condition or improper reference counting mechanism allows attackers to manipulate the audio processing pipeline in such a way that previously freed memory locations remain accessible. This use-after-free condition creates a memory corruption scenario where an attacker can control the contents of freed memory and potentially execute arbitrary code. The vulnerability specifically enables out-of-bounds memory reads, which can expose sensitive data from the browser's memory space or allow for more sophisticated exploitation techniques.
From an operational perspective, this vulnerability presents a severe risk to users as it enables remote code execution through web-based attacks. The attack vector requires only that a user visits a malicious website, making it particularly dangerous for phishing campaigns and drive-by download scenarios. The out-of-bounds memory read capability allows attackers to potentially extract sensitive information from memory, including user credentials, session tokens, or other confidential data. This vulnerability aligns with CWE-416, which describes the use-after-free condition, and can be mapped to ATT&CK technique T1059.007 for script-based execution and T1068 for local privilege escalation. The exploitability is high due to the browser-based attack surface and the fact that no user interaction beyond visiting a malicious page is required.
The mitigation strategy for CVE-2017-5129 primarily involves updating to Chrome version 62.0.3202.62 or later, which contains the necessary patches to address the memory management issues in the WebAudio implementation. Organizations should prioritize immediate deployment of this security update across all affected systems. Additionally, implementing browser hardening measures such as sandboxing, content security policies, and restricting audio processing capabilities in untrusted contexts can provide additional defense layers. Network-level protections including web application firewalls and URL filtering can help prevent access to known malicious domains. Security teams should also monitor for exploitation attempts through network traffic analysis and endpoint detection systems, as the vulnerability may be exploited in targeted campaigns. The patch addresses the root cause by implementing proper memory management controls and ensuring that audio buffer references are properly tracked and validated before memory deallocation occurs.