CVE-2011-3896 in Chrome
Summary
by MITRE
Buffer overflow in Google Chrome before 15.0.874.120 allows remote attackers to cause a denial of service or possibly have unspecified other impact via vectors related to shader variable mapping.
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Analysis
by VulDB Data Team • 11/26/2021
The vulnerability identified as CVE-2011-3896 represents a critical buffer overflow flaw affecting Google Chrome versions prior to 15.0.874.120. This security issue resides within the browser's handling of shader variable mapping operations, which are essential components of WebGL graphics rendering functionality. The vulnerability stems from inadequate bounds checking during the processing of graphics shader variables, creating an exploitable condition that can be triggered through malicious web content. The flaw specifically impacts the graphics processing unit rendering pipeline where shader programs are compiled and executed, making it particularly dangerous in the context of modern web browsing where graphics-intensive applications are increasingly common.
The technical implementation of this vulnerability involves the improper handling of memory allocation when processing shader variable mappings in Chrome's graphics subsystem. Attackers can craft malicious web pages containing specially crafted WebGL shader code that triggers a buffer overflow condition during shader compilation. This occurs when the browser attempts to map shader variables to memory locations without sufficient validation of input parameters, leading to memory corruption that can result in arbitrary code execution or system instability. The vulnerability is classified under CWE-121 as a stack-based buffer overflow, representing a fundamental flaw in memory management where insufficient bounds checking allows data to overwrite adjacent memory locations. The attack surface is expanded through the use of WebGL APIs which are designed to provide hardware-accelerated graphics rendering capabilities but become weaponized through improper input validation.
The operational impact of CVE-2011-3896 extends beyond simple denial of service conditions to potentially enable remote code execution and system compromise. When exploited successfully, this vulnerability allows attackers to execute arbitrary code within the context of the Chrome browser process, potentially leading to full system compromise depending on the victim's privileges and system configuration. The vulnerability affects all users of affected Chrome versions regardless of their security awareness or system hardening measures, as the attack vector operates entirely through web-based content. The exploitability is enhanced by the fact that WebGL functionality is enabled by default in modern browsers, making it accessible to attackers without requiring user interaction beyond visiting a malicious website. This vulnerability also aligns with ATT&CK technique T1059.007 for command and scripting interpreter, as the exploitation process can lead to command execution within the browser environment, potentially enabling further attack progression.
Mitigation strategies for CVE-2011-3896 primarily focus on immediate software updates and browser security hardening measures. The most effective remediation involves upgrading to Google Chrome version 15.0.874.120 or later, which includes patches addressing the buffer overflow conditions in shader variable mapping. Organizations should implement automated update mechanisms to ensure rapid deployment of security patches across all systems. Additional defensive measures include implementing browser security policies that restrict WebGL functionality, using content filtering solutions to block malicious web content, and deploying network-based intrusion detection systems to monitor for exploitation attempts. The vulnerability highlights the importance of comprehensive input validation and memory safety practices in graphics rendering libraries, emphasizing the need for regular security assessments of browser components that handle complex graphics operations. Security teams should also consider implementing sandboxing mechanisms and privilege separation techniques to limit the potential impact of successful exploitation attempts.