CVE-2012-2862 in Chrome
Summary
by MITRE
Use-after-free vulnerability in the PDF functionality in Google Chrome before 21.0.1180.75 allows remote attackers to cause a denial of service or possibly have unspecified other impact via a crafted document.
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Analysis
by VulDB Data Team • 03/27/2021
The vulnerability identified as CVE-2012-2862 represents a critical use-after-free flaw within Google Chrome's PDF rendering engine, specifically affecting versions prior to 21.0.1180.75. This type of vulnerability occurs when a program continues to reference memory that has already been freed, creating a scenario where malicious actors can manipulate memory access patterns to execute arbitrary code or cause system instability. The issue resides in the PDF functionality component of the browser, which processes and renders pdf documents through chrome's integrated pdf viewer.
The technical exploitation of this use-after-free vulnerability leverages the improper memory management within chrome's pdf parsing routines. When processing malformed or crafted pdf documents, the browser's pdf engine fails to properly validate memory allocations and deallocations, allowing attackers to craft malicious pdf files that trigger the vulnerable code path. This flaw typically manifests when the pdf parser encounters specific object structures that cause memory to be freed while still being referenced elsewhere in the parsing process. The vulnerability is particularly dangerous because it can be triggered through web-based pdf documents, making it exploitable via standard web browsing without requiring any special privileges or user interaction beyond visiting a malicious website.
The operational impact of CVE-2012-2862 extends beyond simple denial of service scenarios, as the use-after-free condition creates opportunities for more severe exploitation techniques. Attackers can potentially leverage this vulnerability to execute arbitrary code within the context of the chrome process, which could lead to complete system compromise given the privileges available to browser processes. The unspecified other impacts mentioned in the vulnerability description suggest that this flaw may enable privilege escalation, information disclosure, or other advanced persistent threat capabilities that could be exploited in targeted attacks. This vulnerability aligns with CWE-416, which specifically addresses use-after-free conditions in software applications, and could map to ATT&CK technique T1059.007 for command and control through web browsers.
Mitigation strategies for this vulnerability require immediate patching of affected chrome versions to the patched release 21.0.1180.75 or later, which contains proper memory management fixes for the pdf parsing routines. Organizations should implement browser hardening measures including disabling pdf viewer functionality where possible, using alternative pdf readers, and implementing web application firewalls that can detect and block suspicious pdf content. Additional defensive measures include regular browser updates, network monitoring for suspicious pdf file downloads, and user education regarding the risks of visiting untrusted websites with pdf content. The vulnerability highlights the importance of memory safety in browser components and demonstrates how pdf processing engines represent high-value targets for attackers seeking to exploit browser vulnerabilities, making regular security assessments of browser plugins and integrated components essential for maintaining secure computing environments.