CVE-2012-1946 in Firefox
Summary
by MITRE
Use-after-free vulnerability in the nsINode::ReplaceOrInsertBefore function in Mozilla Firefox 4.x through 12.0, Firefox ESR 10.x before 10.0.5, Thunderbird 5.0 through 12.0, Thunderbird ESR 10.x before 10.0.5, and SeaMonkey before 2.10 might allow remote attackers to execute arbitrary code via document changes involving replacement or insertion of a node.
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Analysis
by VulDB Data Team • 10/21/2024
The CVE-2012-1946 vulnerability represents a critical use-after-free flaw within the document object model processing capabilities of several Mozilla applications including Firefox, Thunderbird, and SeaMonkey. This vulnerability specifically targets the nsINode::ReplaceOrInsertBefore function which handles the manipulation of DOM nodes during document modifications. The flaw occurs when the application processes document changes involving the replacement or insertion of nodes, creating a scenario where memory previously allocated to a DOM node is accessed after it has been freed, potentially allowing malicious actors to execute arbitrary code on affected systems.
The technical exploitation of this vulnerability relies on the improper memory management within the browser's rendering engine, specifically in how it handles node replacement operations. When a document modification occurs through the ReplaceOrInsertBefore function, the application fails to properly validate the memory state of nodes being manipulated, leading to a situation where freed memory locations can be accessed and potentially overwritten with malicious code. This type of vulnerability falls under the CWE-416 category of Use After Free, which is classified as a common weakness in software security practices and is particularly dangerous in browser environments where arbitrary code execution can lead to complete system compromise. The vulnerability demonstrates a classic memory safety issue that has been a persistent challenge in web browser development due to the complex nature of DOM manipulation and memory management in dynamic web environments.
The operational impact of this vulnerability extends beyond simple code execution, as it provides attackers with a pathway to gain unauthorized access to affected systems. Attackers can craft malicious web pages that trigger the vulnerable code path through document modifications, potentially leading to privilege escalation, data theft, or complete system control. The vulnerability affects multiple versions across the Mozilla ecosystem, making it particularly dangerous as it impacts both regular browser releases and extended support releases. The fact that this vulnerability exists in versions through Firefox 12.0 and Thunderbird 12.0 indicates that it remained unfixed for an extended period, increasing the potential attack surface and making it a significant concern for organizations using these applications.
Mitigation strategies for this vulnerability require immediate patching of affected applications to the latest available versions that contain the necessary memory management fixes. Organizations should prioritize updating Firefox, Thunderbird, and SeaMonkey installations to versions that have addressed this specific use-after-free condition. Additionally, implementing browser hardening measures such as disabling JavaScript in untrusted environments, using content security policies, and deploying web application firewalls can provide additional layers of protection. The vulnerability also highlights the importance of regular security assessments and vulnerability management programs that can identify and remediate similar memory safety issues before they can be exploited in the wild. According to ATT&CK framework, this vulnerability maps to T1059.007 for Command and Scripting Interpreter and T1078.004 for Valid Accounts, as successful exploitation could lead to persistent access and command execution within compromised systems.