CVE-2010-0167 in Firefox
Summary
by MITRE
The browser engine in Mozilla Firefox 3.0.x before 3.0.18, 3.5.x before 3.5.8, and 3.6.x before 3.6.2; Thunderbird before 3.0.2; and SeaMonkey before 2.0.3 allows remote attackers to cause a denial of service (memory corruption and application crash) and possibly execute arbitrary code via vectors related to (1) layout/generic/nsBlockFrame.cpp and (2) the _evaluate function in modules/plugin/base/src/nsNPAPIPlugin.cpp.
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Analysis
by VulDB Data Team • 05/03/2026
This vulnerability affects multiple Mozilla products including Firefox, Thunderbird, and SeaMonkey, representing a critical memory corruption issue that could lead to remote code execution or denial of service. The flaw exists in the browser engine's handling of specific code paths within the layout system and plugin processing components. The vulnerability is particularly concerning as it affects versions prior to specific security patches, with Firefox 3.0.x before 3.0.18, 3.5.x before 3.5.8, and 3.6.x before 3.6.2 being impacted, alongside Thunderbird before 3.0.2 and SeaMonkey before 2.0.3. The vulnerability stems from improper memory management in two distinct code locations that handle layout rendering and plugin evaluation respectively.
The technical implementation of this vulnerability involves memory corruption that occurs during the processing of web content through the layout engine's block frame handling in nsBlockFrame.cpp and through the plugin evaluation function _evaluate in nsNPAPIPlugin.cpp. When malicious content is processed by these components, the improper memory handling causes buffer overflows or use-after-free conditions that can result in application crashes or potentially allow attackers to execute arbitrary code on the victim's system. These code paths are typically triggered when processing specially crafted web pages that contain malformed content designed to exploit the memory handling flaws. The vulnerability demonstrates characteristics consistent with CWE-121, heap-based buffer overflow, and CWE-122, stack-based buffer overflow, as well as CWE-787, out-of-bounds write, which are commonly exploited in browser engine vulnerabilities.
The operational impact of this vulnerability extends beyond simple denial of service to include potential remote code execution capabilities, making it particularly dangerous in enterprise environments where users may encounter malicious web content. Attackers could craft web pages that, when loaded in affected browsers, would trigger the memory corruption conditions and potentially allow them to execute malicious code with the privileges of the user running the browser. The vulnerability affects a wide range of Mozilla products, increasing the potential attack surface significantly. Users of these affected versions face substantial risk when browsing the internet, as the exploitation can occur through standard web page loading without requiring any special user interaction beyond visiting a malicious website. The vulnerability also impacts email clients like Thunderbird, where malicious email attachments or HTML content could trigger similar exploitation scenarios.
Mitigation strategies for this vulnerability require immediate patching of all affected Mozilla products to the specified secure versions. Organizations should implement comprehensive patch management processes to ensure all affected systems receive updates promptly, as the vulnerability affects multiple product lines within the Mozilla ecosystem. Network administrators should consider implementing web filtering solutions that can detect and block access to known malicious domains that might host exploit code. Additionally, users should be educated about the risks of visiting untrusted websites and opening suspicious email attachments. Security teams should monitor for indicators of compromise related to this vulnerability and consider implementing intrusion detection systems that can identify exploitation attempts. The vulnerability also highlights the importance of maintaining up-to-date security patches across all browser and email client installations, as these types of memory corruption vulnerabilities are frequently targeted in zero-day exploit campaigns. This vulnerability aligns with ATT&CK technique T1203, Exploitation for Client Execution, and T1059, Command and Scripting Interpreter, as it enables attackers to execute arbitrary code through browser-based exploitation.