CVE-2016-5156 in Chrome
Summary
by MITRE
extensions/renderer/event_bindings.cc in the event bindings in Google Chrome before 53.0.2785.89 on Windows and OS X and before 53.0.2785.92 on Linux attempts to process filtered events after failure to add an event matcher, which allows remote attackers to cause a denial of service (use-after-free) or possibly have unspecified other impact via unknown vectors.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 09/14/2022
The vulnerability described in CVE-2016-5156 represents a critical use-after-free condition within Google Chrome's event bindings implementation on multiple operating systems. This flaw exists in the extensions/renderer/event_bindings.cc file where the browser processes filtered events without proper error handling when event matcher addition fails. The issue affects Chrome versions prior to 53.0.2785.89 on Windows and OS X, and before 53.0.2785.92 on Linux, making it a widespread concern across the Chrome ecosystem. The vulnerability stems from inadequate memory management practices where the system continues to reference freed memory locations, creating potential attack vectors for remote threat actors.
The technical implementation of this vulnerability involves the event binding subsystem within Chrome's extension framework where event matchers are added to track browser events. When the system fails to successfully add an event matcher due to various conditions such as memory allocation failures or invalid parameters, the code path continues to process events that should have been filtered out. This creates a scenario where freed memory locations are accessed, leading to the use-after-free condition. The flaw manifests when Chrome attempts to process events that were supposed to be filtered based on specific criteria but were not properly handled due to the failed matcher addition. This behavior can result in memory corruption that potentially allows attackers to execute arbitrary code or cause system instability.
The operational impact of CVE-2016-5156 extends beyond simple denial of service to potentially enable more severe compromise scenarios. While the primary effect is described as denial of service through use-after-free conditions, the unspecified other impacts mentioned in the CVE description suggest potential for privilege escalation or remote code execution. Attackers could leverage this vulnerability by crafting malicious extensions or web pages that trigger the specific code path where event matcher addition fails, then manipulate the event processing to access freed memory. This aligns with attack patterns documented in the attack tactics and techniques framework where adversaries exploit memory corruption vulnerabilities to gain system control. The vulnerability's presence in Chrome's extension system makes it particularly dangerous as extensions often have elevated privileges and can access sensitive browser functionality.
Mitigation strategies for CVE-2016-5156 focus primarily on immediate patching and system updates to the affected Chrome versions. Organizations should prioritize updating to Chrome versions 53.0.2785.89 or later on Windows and OS X, and 53.0.2785.92 or later on Linux to eliminate the vulnerability. Additionally, implementing browser hardening measures such as sandboxing, disabling unnecessary extensions, and restricting extension installation from untrusted sources provides additional defense layers. Security monitoring should focus on detecting unusual browser behavior or memory access patterns that might indicate exploitation attempts. The vulnerability's classification under CWE-416 indicates it falls within the category of improper cleanup of memory resources, making it a clear target for defensive security measures that focus on memory safety and proper resource management practices. Network security controls should also monitor for exploitation attempts targeting this specific memory corruption pattern.
The broader implications of this vulnerability highlight the importance of robust error handling in complex browser architectures, particularly in extension frameworks where memory management becomes increasingly critical. This flaw demonstrates how seemingly minor implementation details in event processing can create significant security risks when error conditions are not properly handled. The vulnerability's existence across multiple platforms underscores the need for consistent security practices throughout browser codebases and emphasizes the importance of thorough testing for edge cases in event handling systems. Security professionals should consider this vulnerability as part of a larger pattern of memory safety issues in web browsers and implement comprehensive testing strategies that include memory access validation and error condition handling verification.