CVE-2008-2811 in Firefox
Summary
by MITRE
The block reflow implementation in Mozilla Firefox before 2.0.0.15, Thunderbird 2.0.0.14 and earlier, and SeaMonkey before 1.1.10 allows remote attackers to execute arbitrary code or cause a denial of service (application crash) via an image whose display requires more pixels than nscoord_MAX, related to nsBlockFrame::DrainOverflowLines.
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Analysis
by VulDB Data Team • 12/30/2024
The vulnerability described in CVE-2008-2811 represents a critical buffer overflow condition within the rendering engine of several Mozilla-based applications including Firefox, Thunderbird, and SeaMonkey. This flaw exists in the block reflow implementation mechanism that handles the layout and display of web content. The issue specifically manifests when processing images that require excessive pixel calculations during the rendering process, creating a scenario where the application's coordinate handling system becomes overwhelmed. The technical implementation involves the nsBlockFrame::DrainOverflowLines function which manages overflow line processing during content layout operations. When an attacker crafts a malicious image that requires more pixels than the predefined nscoord_MAX limit, the application's internal coordinate system fails to properly handle this overflow condition, leading to unpredictable behavior.
The operational impact of this vulnerability spans both remote code execution and denial of service scenarios, making it particularly dangerous for widespread exploitation. Attackers can leverage this flaw by embedding specially crafted images within web pages or email content that, when rendered by vulnerable applications, trigger the overflow condition. The vulnerability's classification aligns with CWE-129, which addresses improper validation of length of inputs to buffer operations, and CWE-190, which covers integer overflow or wraparound conditions. From an attacker's perspective, this represents a significant vector for compromising user systems since the exploit can be delivered through standard web browsing or email interactions. The specific function nsBlockFrame::DrainOverflowLines acts as the attack surface where integer overflow conditions lead to memory corruption that can be leveraged for arbitrary code execution.
The exploitation of this vulnerability demonstrates the complexity of modern browser security architectures and the challenges inherent in managing coordinate systems within rendering engines. The flaw occurs during the application's layout phase when it attempts to calculate display dimensions for content that exceeds normal processing limits, creating a scenario where the application's internal coordinate handling system becomes corrupted. This vulnerability specifically affects versions prior to Firefox 2.0.0.15, Thunderbird 2.0.0.14, and SeaMonkey 1.1.10, highlighting the importance of timely security updates in maintaining application integrity. The attack pattern follows typical exploitation techniques described in the MITRE ATT&CK framework under the T1203 technique for exploitation of remote services, where attackers leverage application-specific vulnerabilities to achieve system compromise. Organizations and users must understand that this vulnerability represents a fundamental flaw in how these applications handle edge cases in their rendering systems, emphasizing the need for robust input validation and memory management practices. The remediation requires immediate patching of affected applications and implementation of additional security measures such as content filtering and sandboxing to limit potential impact from successful exploitation attempts.