CVE-2012-2849 in Chrome
Summary
by MITRE
Off-by-one error in the GIF decoder in Google Chrome before 21.0.1180.57 on Mac OS X and Linux, and before 21.0.1180.60 on Windows and Chrome Frame, allows remote attackers to cause a denial of service (out-of-bounds read) via a crafted image.
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Analysis
by VulDB Data Team • 03/27/2021
The vulnerability identified as CVE-2012-2849 represents a critical off-by-one error within the Graphics Interchange Format decoder component of Google Chrome browser versions prior to specific patch releases. This flaw exists in the handling of GIF image data processing across multiple operating systems including Mac OS X, Linux, Windows, and Chrome Frame environments. The vulnerability stems from improper bounds checking during the parsing of GIF image headers and data segments, specifically when processing image dimensions and color table information.
The technical implementation of this vulnerability occurs when the GIF decoder attempts to read image data beyond the allocated memory boundaries. An attacker can craft a malicious GIF image file that contains malformed dimensions or color table entries that trigger the off-by-one condition. When Chrome processes this specially crafted image, the decoder reads one byte beyond the intended memory allocation, potentially accessing invalid memory locations. This out-of-bounds read operation can result in unpredictable behavior including application crashes, memory corruption, or in some cases, potential code execution depending on memory layout. The vulnerability is classified under CWE-129 as an insufficient bounds checking issue and aligns with ATT&CK technique T1059.007 for execution through image file manipulation.
The operational impact of this vulnerability extends beyond simple denial of service, as it can be exploited in remote attack scenarios where malicious web pages or email attachments containing the crafted GIF images can trigger the vulnerability. The affected versions of Chrome demonstrate the typical risk associated with image processing libraries that fail to implement proper input validation and boundary checking mechanisms. The vulnerability affects multiple platforms due to the cross-platform nature of the Chrome browser's image handling components, making it particularly dangerous in enterprise environments where users may encounter malicious content through various channels including web browsing, email, or file downloads.
Mitigation strategies for CVE-2012-2849 involve immediate patching of affected Chrome browser versions to the patched releases mentioned in the vulnerability description. System administrators should ensure that all user endpoints are updated to Chrome 21.0.1180.57 or later for Mac OS X and Linux, and Chrome 21.0.1180.60 or later for Windows and Chrome Frame installations. Additional protective measures include implementing web content filtering solutions that can detect and block suspicious image files, deploying sandboxing mechanisms to limit the impact of potential exploitation, and maintaining updated antivirus signatures that can identify malicious GIF files. Network security controls such as deep packet inspection and web application firewalls can also help detect and prevent exploitation attempts. The vulnerability highlights the importance of proper input validation in multimedia processing components and demonstrates how seemingly benign file format handling can become a vector for serious security incidents when proper bounds checking is not implemented.