CVE-2012-1974 in Firefox
Summary
by MITRE
Use-after-free vulnerability in the gfxTextRun::CanBreakLineBefore function in Mozilla Firefox before 15.0, Firefox ESR 10.x before 10.0.7, Thunderbird before 15.0, Thunderbird ESR 10.x before 10.0.7, and SeaMonkey before 2.12 allows remote attackers to execute arbitrary code or cause a denial of service (heap memory corruption) via unspecified vectors.
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Analysis
by VulDB Data Team • 10/22/2024
The CVE-2012-1974 vulnerability represents a critical use-after-free flaw within the graphics text rendering subsystem of Mozilla Firefox and related applications. This vulnerability specifically affects the gfxTextRun::CanBreakLineBefore function which handles text line breaking operations during rendering. The flaw occurs when the application processes text that requires line breaking calculations, creating conditions where freed memory objects are accessed after their original allocation has been released. Such memory corruption issues are particularly dangerous because they can be exploited to execute arbitrary code with the privileges of the affected application, making them prime targets for remote exploitation.
The technical nature of this vulnerability stems from improper memory management within the graphics rendering pipeline. When the CanBreakLineBefore function processes text elements, it may release memory resources associated with text run objects while simultaneously maintaining references to those freed locations. This creates a window where malicious input can trigger the function to access previously freed memory, leading to heap corruption. The vulnerability is classified under CWE-416 as Use After Free, which is a well-documented weakness in software security where a program continues to use a pointer after the memory it points to has been freed. This particular implementation flaw allows attackers to manipulate the heap state through carefully crafted input that forces the application to perform invalid memory operations.
The operational impact of this vulnerability extends beyond simple denial of service scenarios to encompass full remote code execution capabilities. Attackers can leverage this flaw by crafting malicious web content or email messages that contain specially formatted text elements designed to trigger the vulnerable code path. When the affected application processes such content, the heap corruption can be manipulated to overwrite critical memory structures, potentially allowing attackers to inject and execute arbitrary code on the target system. This makes the vulnerability particularly dangerous in web browser environments where users frequently encounter untrusted content. The vulnerability affects multiple Mozilla products including Firefox, Thunderbird, and SeaMonkey, demonstrating the widespread nature of the flaw across the Mozilla ecosystem and highlighting the importance of coordinated security updates.
Mitigation strategies for CVE-2012-1974 require immediate application of vendor security patches and updates to the affected software versions. Organizations should prioritize updating to Firefox 15.0, Firefox ESR 10.0.7, Thunderbird 15.0, Thunderbird ESR 10.0.7, and SeaMonkey 2.12 or later versions that contain the necessary fixes. Additionally, network administrators should implement security measures such as content filtering and web application firewalls to reduce the risk of exploitation. The vulnerability aligns with ATT&CK technique T1059.007 for Command and Scripting Interpreter and T1203 for Exploitation for Client Execution, as it enables attackers to execute malicious code through compromised applications. Security monitoring should focus on detecting unusual memory access patterns and heap corruption indicators within browser processes, while regular security assessments should verify that all affected systems have been properly patched and that no legacy installations remain vulnerable to this and similar memory corruption flaws.