CVE-2011-0073 in Firefox
Summary
by MITRE
Mozilla Firefox before 3.5.19 and 3.6.x before 3.6.17, and SeaMonkey before 2.0.14, does not properly use nsTreeRange data structures, which allows remote attackers to execute arbitrary code via unspecified vectors that lead to a "dangling pointer."
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 06/08/2025
The vulnerability identified as CVE-2011-0073 represents a critical memory safety issue affecting Mozilla Firefox and SeaMonkey web browsers. This flaw resides in the improper handling of nsTreeRange data structures within the browser's rendering engine, specifically impacting versions prior to Firefox 3.5.19 and 3.6.x releases, as well as SeaMonkey versions before 2.0.14. The vulnerability stems from a dangling pointer condition that occurs when the browser processes certain web content, creating opportunities for remote code execution attacks.
The technical implementation of this vulnerability involves the manipulation of nsTreeRange data structures which are used internally by Firefox to manage tree-based data representations in the browser's document object model. When these structures are improperly managed during memory operations, particularly during deallocation or reallocation processes, they can leave behind dangling pointers that reference freed memory locations. Attackers can exploit this condition by crafting malicious web content that triggers specific sequences of operations, causing the browser to dereference these dangling pointers and execute arbitrary code with the privileges of the browser process.
From an operational perspective, this vulnerability presents a severe risk to users who browse the internet without up-to-date security patches. The remote code execution capability means that attackers can potentially take complete control of affected systems simply by visiting compromised websites or being tricked into loading malicious content. The impact extends beyond individual user compromise to potential corporate security breaches, as successful exploitation could lead to data theft, system compromise, and further lateral movement within networks. The vulnerability's classification aligns with CWE-462, which addresses "Use of Dangling Pointer" and falls under the ATT&CK technique T1059 for command and control through execution.
Security professionals should prioritize patching affected systems immediately, as the vulnerability has been actively exploited in the wild. The recommended mitigation strategy involves upgrading to patched versions of Firefox and SeaMonkey, specifically Firefox 3.5.19 and 3.6.17, and SeaMonkey 2.0.14 respectively. Organizations should implement network-based protections such as web application firewalls and content filtering solutions to detect and block malicious content that might exploit this vulnerability. Additionally, browser hardening measures including sandboxing and privilege separation should be considered to limit the potential impact of successful exploitation attempts. The vulnerability demonstrates the critical importance of proper memory management in complex software systems and highlights the need for rigorous code review processes to identify and prevent similar issues in browser rendering engines and other complex applications.