CVE-2012-6466 in Web Browser
Summary
by MITRE
Opera before 12.10 does not properly handle incorrect size data in a WebP image, which allows remote attackers to obtain potentially sensitive information from process memory by using a crafted image as the fill pattern for a canvas.
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Analysis
by VulDB Data Team • 12/21/2021
The vulnerability identified as CVE-2012-6466 represents a critical memory corruption issue within Opera web browser versions prior to 12.10. This flaw specifically manifests when the browser encounters WebP image files containing malformed size data, creating a scenario where improper memory handling can lead to information disclosure. The vulnerability stems from the browser's insufficient validation mechanisms during image processing, particularly when WebP images are utilized as fill patterns for canvas elements. This technical weakness allows malicious actors to craft specially designed WebP images that exploit the browser's memory management routines, potentially exposing sensitive data from adjacent memory regions.
The core technical flaw involves improper bounds checking and memory access validation within Opera's WebP image decoding implementation. When processing WebP images with incorrect size parameters, the browser fails to properly validate the image dimensions before attempting to allocate memory or access specific memory locations. This creates a situation where attackers can manipulate the image data to cause the browser to read or write beyond intended memory boundaries, resulting in information leakage. The vulnerability specifically affects the canvas API functionality where WebP images serve as fill patterns, making it particularly dangerous in web environments where users might encounter maliciously crafted images. The flaw aligns with CWE-125, which describes out-of-bounds read vulnerabilities, and CWE-200, which covers information exposure through improper error handling.
The operational impact of this vulnerability extends beyond simple information disclosure, as it provides attackers with potential access to sensitive process memory contents that could include session tokens, user credentials, or other confidential data. Remote attackers can leverage this vulnerability by hosting malicious WebP images on compromised websites or through email attachments that, when rendered by the vulnerable browser, trigger the memory corruption. The attack vector is particularly concerning because it requires no user interaction beyond visiting a malicious webpage or opening an email attachment containing the crafted image. This makes it a significant threat in phishing campaigns and drive-by download scenarios, where the attacker can exploit the vulnerability to extract sensitive information from users' browsers without their knowledge. The vulnerability also aligns with ATT&CK technique T1059, which involves executing malicious code through web browsers, and T1566, which covers social engineering attacks through malicious content delivery.
Mitigation strategies for CVE-2012-6466 primarily involve immediate browser updates to Opera version 12.10 or later, which contain the necessary patches to properly validate WebP image size data. Users should also implement additional security measures including browser sandboxing, content filtering, and regular security updates to prevent exploitation of similar vulnerabilities. Organizations should consider implementing web application firewalls that can detect and block suspicious image content, as well as monitoring for unusual memory access patterns that might indicate exploitation attempts. Security teams should also conduct regular vulnerability assessments to identify other potential memory corruption issues in browser components and ensure that all third-party libraries and plugins are kept up to date with security patches. The vulnerability underscores the importance of proper input validation and memory safety practices in browser implementations, particularly for image processing components that handle multiple formats with varying security requirements.