CVE-2011-3911 in Chrome
Summary
by MITRE
Google Chrome before 16.0.912.63 does not properly handle PDF documents, which allows remote attackers to cause a denial of service (out-of-bounds read) via unspecified vectors.
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Analysis
by VulDB Data Team • 11/28/2021
The vulnerability identified as CVE-2011-3911 represents a critical security flaw in Google Chrome browsers prior to version 16.0.912.63, specifically within the PDF document handling component. This issue manifests as an out-of-bounds read condition that can be exploited by remote attackers to trigger a denial of service scenario. The vulnerability stems from insufficient input validation and memory management within Chrome's embedded PDF viewer implementation, which is based on the Poppler library and other PDF rendering components. Attackers can craft malicious PDF documents that, when opened in vulnerable Chrome versions, cause the browser to attempt reading memory locations beyond the allocated buffer boundaries, leading to unpredictable behavior and system instability.
The technical exploitation of this vulnerability occurs through the manipulation of PDF document structures that are processed by Chrome's PDF rendering engine. When a malicious PDF is loaded, the parser encounters malformed or specially crafted data elements that cause the memory access violation. This particular flaw falls under the category of memory corruption vulnerabilities and is classified as CWE-125, which represents "Out-of-bounds Read" in the Common Weakness Enumeration catalog. The vulnerability demonstrates a classic buffer over-read scenario where the PDF parser fails to properly validate array indices or memory boundaries before accessing data structures, allowing attackers to bypass normal memory protection mechanisms and execute arbitrary code or cause system crashes.
From an operational perspective, this vulnerability presents significant risk to users who frequently encounter PDF documents from untrusted sources. The denial of service impact means that affected systems can become completely unresponsive or crash entirely when processing malicious PDF files, potentially disrupting business operations and user productivity. The remote nature of the attack vector allows adversaries to deliver malicious payloads through various channels including email attachments, web downloads, and compromised websites. Organizations using older Chrome versions are particularly vulnerable as the exploit can be delivered through simple web navigation without requiring any special privileges or user interaction beyond opening the PDF document. This makes the vulnerability particularly dangerous in enterprise environments where users may inadvertently access compromised content.
The mitigation strategies for CVE-2011-3911 primarily focus on immediate browser updates to versions 16.0.912.63 and later, which contain the necessary patches to address the PDF parsing vulnerabilities. System administrators should implement comprehensive patch management policies to ensure all Chrome installations are updated promptly. Additional protective measures include implementing web content filtering solutions that can detect and block suspicious PDF files, configuring browser security settings to disable automatic PDF rendering, and educating users about the risks of opening PDF documents from unknown sources. Organizations should also consider implementing sandboxing mechanisms and network-based intrusion detection systems that can identify and prevent exploitation attempts. The vulnerability aligns with ATT&CK technique T1203, which covers "Exploitation for Client Execution" and demonstrates how attackers can leverage browser vulnerabilities to execute malicious code or cause system instability, making it a critical component of enterprise security defense-in-depth strategies.