CVE-2012-4213 in Firefox
Summary
by MITRE
Use-after-free vulnerability in the nsEditor::FindNextLeafNode function in Mozilla Firefox before 17.0, Thunderbird before 17.0, and SeaMonkey before 2.14 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-2012-4213 vulnerability represents a critical use-after-free condition affecting Mozilla Firefox versions prior to 17.0, Thunderbird versions prior to 17.0, and SeaMonkey versions prior to 2.14. This flaw resides within the nsEditor::FindNextLeafNode function, which is part of the core editing engine responsible for text manipulation within these applications. The vulnerability stems from improper memory management where freed memory locations are accessed after the memory has been deallocated, creating a dangerous window for exploitation. Such conditions typically arise when the application fails to properly track object lifecycles and maintain valid references to memory that may have been released during normal program execution.
The technical implementation of this vulnerability involves heap memory corruption that occurs when the nsEditor component processes text content containing specific malformed structures. Attackers can craft malicious web content or email messages that trigger the vulnerable code path, causing the application to access memory that has already been freed. This memory corruption can manifest in two primary ways: either through arbitrary code execution when the corrupted memory is manipulated to redirect program flow, or through denial of service when the corruption causes application crashes. The underlying mechanism follows CWE-416, which specifically addresses use-after-free vulnerabilities where memory is accessed after it has been freed, making it a direct implementation of the well-known memory safety issue category.
The operational impact of this vulnerability extends beyond simple exploitation as it affects the fundamental security model of these applications. When successfully exploited, attackers can achieve remote code execution with the privileges of the victim user, potentially leading to complete system compromise. The vulnerability's remote nature makes it particularly dangerous as it can be triggered through web browsing or email processing without requiring user interaction beyond normal application use. This characteristic places the vulnerability in the ATT&CK framework under the Tactic of Execution, specifically targeting the use of malicious content to achieve code execution. The affected applications' widespread use across enterprise and consumer environments amplifies the potential impact, making this vulnerability a high-priority target for threat actors seeking to compromise systems.
Mitigation strategies for CVE-2012-4213 primarily focus on immediate patch deployment, as the vulnerability requires no user interaction to exploit once the malicious content is loaded. Organizations should prioritize updating to versions 17.0 or later for Firefox, 17.0 for Thunderbird, and 2.14 for SeaMonkey, as these releases contain the necessary memory management fixes. Additionally, implementing network-level protections such as content filtering and web application firewalls can provide defense-in-depth measures while patches are being deployed. Browser hardening techniques including sandboxing and privilege separation can also reduce the potential impact of successful exploitation attempts, though they do not prevent the vulnerability itself. The remediation process should include thorough testing of updated applications to ensure compatibility while maintaining security posture, as memory corruption vulnerabilities often require careful handling during patch implementation to avoid introducing new instability.