CVE-2012-5139 in Chrome
Summary
by MITRE
Use-after-free vulnerability in Google Chrome before 23.0.1271.97 allows remote attackers to cause a denial of service or possibly have unspecified other impact via vectors related to visibility events.
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Analysis
by VulDB Data Team • 04/20/2021
The CVE-2012-5139 vulnerability represents a critical use-after-free flaw in Google Chrome versions prior to 23.0.1271.97 that fundamentally compromises the browser's memory management integrity. This vulnerability specifically manifests during the handling of visibility events, which are part of the HTML5 Page Visibility API that allows web pages to detect when they are visible or hidden to the user. The flaw occurs when the browser fails to properly manage memory references after objects are freed, creating opportunities for malicious code to exploit the dangling pointer situation. Such vulnerabilities fall under the CWE-416 category of Use After Free, which is classified as a serious memory safety issue that can lead to arbitrary code execution or system compromise. The vulnerability's exploitation potential is particularly concerning because it can be triggered remotely through web content without requiring any user interaction beyond visiting a malicious website.
The technical implementation of this vulnerability involves the browser's JavaScript engine incorrectly managing object lifecycles when processing visibility change events. When a web page triggers visibility events such as pagehide or pageshow, the underlying memory structures associated with these events may be freed while still being referenced by other code paths. Attackers can craft malicious web pages that manipulate these event handlers in such a way that they cause the browser to access freed memory locations, leading to either immediate crashes or more insidiously, potential code execution. The memory corruption that occurs during this use-after-free scenario can be leveraged to execute arbitrary instructions in the context of the browser process, potentially allowing attackers to escalate privileges or gain full system control. This type of vulnerability is particularly dangerous in modern browser environments where the attack surface is extensive and the privilege boundaries between different processes are often blurred.
The operational impact of CVE-2012-5139 extends beyond simple denial of service conditions to potentially enable full system compromise in targeted attacks. While the vulnerability description mentions unspecified other impacts, the nature of use-after-free conditions in browser environments typically allows for remote code execution, making it a high-severity threat. The vulnerability's exploitability is enhanced by the fact that it requires no user interaction beyond visiting a malicious website, making it particularly dangerous in phishing campaigns or drive-by download scenarios. The attack vector leverages the Page Visibility API, which is commonly used by legitimate web applications for performance optimization and user experience enhancement, making the vulnerability harder to detect through traditional security scanning methods. This vulnerability also aligns with ATT&CK technique T1059.007 for scripting and T1566.001 for spearphishing attachments, as attackers can leverage it in social engineering campaigns to deliver malicious payloads that exploit the browser's memory management flaws.
Mitigation strategies for this vulnerability primarily focus on immediate remediation through browser updates, as Google released version 23.0.1271.97 to address the specific memory management issues. Organizations should implement comprehensive patch management procedures to ensure all users have the latest Chrome versions installed, particularly in enterprise environments where legacy systems may be at risk. Browser hardening techniques including sandboxing, address space layout randomization, and heap metadata protection can provide additional defense-in-depth measures against exploitation attempts. Security monitoring should include detection of unusual memory access patterns and visibility event handling that might indicate exploitation attempts. Network-based detection systems should be configured to identify malicious web content that attempts to trigger use-after-free conditions, particularly in web applications that heavily utilize the Page Visibility API. The vulnerability also underscores the importance of regular security assessments and code reviews focused on memory management practices, particularly in JavaScript engines and web rendering components. Organizations should also consider implementing web application firewalls and content security policies to limit exposure to malicious web content that could exploit such browser vulnerabilities.