CVE-2006-2784 in Firefox
Summary
by MITRE
The PLUGINSPAGE functionality in Mozilla Firefox before 1.5.0.4 allows remote user-assisted attackers to execute privileged code by tricking a user into installing missing plugins and selecting the "Manual Install" button, then using nested javascript: URLs. NOTE: the manual install button is used for downloading software from a remote web site, so this issue would not cross privilege boundaries if the user progresses to the point of installing malicious software from the attacker-controlled site.
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Analysis
by VulDB Data Team • 06/20/2019
The vulnerability described in CVE-2006-2784 represents a sophisticated privilege escalation attack vector within Mozilla Firefox's plugin management system. This flaw existed in Firefox versions prior to 1.5.0.4 and exploited the PLUGINSPAGE functionality to enable remote attackers to execute privileged code through social engineering techniques. The attack requires user interaction and manipulation of the browser's plugin installation workflow, making it particularly dangerous as it leverages the trust users place in the browser's installation interface. The vulnerability operates through a carefully orchestrated sequence where attackers trick users into initiating plugin installation processes, then exploit the manual install button to execute malicious JavaScript code.
The technical implementation of this vulnerability stems from insufficient input validation and privilege boundary enforcement within Firefox's plugin management subsystem. When users encounter missing plugins, the browser presents a manual installation option that, under normal circumstances, should only facilitate downloading software from remote websites. However, the flaw allowed attackers to craft nested javascript: URLs that could execute code with elevated privileges within the browser's security context. This represents a classic case of insufficient access control and privilege separation, where the manual install functionality was not properly sandboxed or restricted from executing arbitrary code. The vulnerability aligns with CWE-284, which addresses improper access control, and demonstrates how seemingly benign user interface elements can become attack vectors when proper privilege boundaries are not enforced.
The operational impact of this vulnerability extends beyond simple code execution to potentially enable full browser compromise and system infiltration. Attackers could leverage this vulnerability to install malicious software, steal user credentials, monitor browsing activity, or establish persistent backdoors on affected systems. The attack requires user participation but the social engineering aspect makes it particularly effective as users often trust the browser's installation prompts and may not recognize the malicious nature of the nested javascript: URLs. This vulnerability highlights the critical importance of validating user inputs and maintaining strict privilege boundaries even within trusted browser interfaces. The attack vector demonstrates how attackers can exploit the trust model of web browsers to bypass security mechanisms, potentially leading to complete system compromise.
Mitigation strategies for this vulnerability require both immediate patching and enhanced security awareness practices. Organizations should prioritize updating Firefox installations to version 1.5.0.4 or later, which contains the necessary security fixes to prevent exploitation of this vulnerability. Browser security configurations should include additional restrictions on javascript: URL handling and plugin installation processes, though these measures must balance security with usability. The vulnerability also underscores the importance of user education about recognizing potentially malicious installation prompts and the dangers of clicking on untrusted download links. From an ATT&CK framework perspective, this vulnerability maps to privilege escalation techniques and social engineering attacks, emphasizing the need for layered security approaches that protect against both technical flaws and human factors in cybersecurity. Security teams should implement monitoring for suspicious plugin installation activities and consider network-level controls to restrict access to known malicious domains that might host exploit payloads.