CVE-2012-0472 in Firefox
Summary
by MITRE
The cairo-dwrite implementation in Mozilla Firefox 4.x through 11.0, Firefox ESR 10.x before 10.0.4, Thunderbird 5.0 through 11.0, Thunderbird ESR 10.x before 10.0.4, and SeaMonkey before 2.9, when certain Windows Vista and Windows 7 configurations are used, does not properly restrict font-rendering attempts, which allows remote attackers to cause a denial of service (memory corruption) or possibly execute arbitrary code via unspecified vectors.
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Analysis
by VulDB Data Team • 10/21/2024
The vulnerability identified as CVE-2012-0472 represents a critical security flaw within the cairo-dwrite graphics rendering component of Mozilla Firefox and related applications. This issue specifically affects versions ranging from Firefox 4.x through 11.0, Firefox ESR 10.x before 10.0.4, Thunderbird 5.0 through 11.0, Thunderbird ESR 10.x before 10.0.4, and SeaMonkey before 2.9. The flaw manifests when certain Windows Vista and Windows 7 configurations are present, creating an environment where font rendering operations become exploitable. The technical implementation resides in the cairo-dwrite backend which handles DirectWrite font rendering on Windows platforms, making this vulnerability particularly dangerous in enterprise environments where these operating systems are prevalent.
The core technical flaw stems from insufficient validation and restriction of font-rendering operations within the graphics subsystem. When processing certain font files or rendering scenarios, the cairo-dwrite implementation fails to properly validate input parameters and memory boundaries, leading to potential memory corruption vulnerabilities. This weakness allows attackers to craft malicious web content that, when rendered by the affected browsers, can trigger buffer overflows or other memory corruption conditions. The vulnerability operates at the intersection of graphics rendering and memory management, where improper bounds checking enables attackers to manipulate memory layout and potentially execute arbitrary code. The flaw is categorized under CWE-125 as an out-of-bounds read and potentially CWE-787 as an out-of-bounds write, both of which are fundamental memory safety issues that can lead to complete system compromise.
The operational impact of this vulnerability extends beyond simple denial of service scenarios, as the memory corruption conditions can potentially be leveraged for remote code execution. Attackers can craft malicious web pages that, when loaded in affected browsers, trigger the vulnerable font rendering path and exploit the memory corruption to gain arbitrary code execution privileges. This creates a significant threat vector for enterprise environments where users may encounter malicious content through phishing attacks, compromised websites, or social engineering campaigns. The vulnerability is particularly concerning because it operates at the graphics rendering layer, making it difficult to detect through traditional network-based security controls and potentially bypassing many application-level security measures.
Mitigation strategies for CVE-2012-0472 primarily focus on immediate version upgrades to patched releases of affected software. Organizations should prioritize updating Firefox, Thunderbird, and SeaMonkey to versions that contain the necessary security patches, with particular attention to Firefox ESR 10.0.4 and later releases, Thunderbird ESR 10.0.4, and SeaMonkey 2.9 or higher. System administrators should also consider implementing additional protective measures including browser hardening configurations, content filtering solutions, and network-based intrusion detection systems that can identify and block malicious font-related content. The vulnerability demonstrates the importance of proper input validation in graphics rendering components and aligns with ATT&CK technique T1059.007 for execution through web browsers, making it a critical target for security hardening efforts. Organizations should also monitor for indicators of compromise related to font rendering anomalies and implement regular security assessments of their browser environments to prevent exploitation of similar vulnerabilities in the future.