CVE-2005-0590 in Firefox
Summary
by MITRE
The installation confirmation dialog in Firefox before 1.0.1, Thunderbird before 1.0.1, and Mozilla before 1.7.6 allows remote attackers to use InstallTrigger to spoof the hostname of the host performing the installation via a long "user:pass" sequence in the URL, which appears before the real hostname.
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Analysis
by VulDB Data Team • 05/31/2019
This vulnerability resides in the installation confirmation dialog mechanism of Mozilla-based browsers including firefox thunderbird and mozilla itself. The flaw manifests when these applications process installation requests through the InstallTrigger API which is designed to handle add-on installations. The vulnerability stems from insufficient validation of URLs within the installation confirmation process where the hostname extraction logic fails to properly parse URLs containing excessively long username and password sequences. When a malicious actor crafts a URL with an extended user:pass sequence preceding the actual hostname, the browser's parsing routine incorrectly identifies the spoofed portion as the legitimate host name during the installation confirmation dialog.
The technical implementation of this vulnerability exploits the way these browsers handle URL parsing specifically within the installation context. The InstallTrigger API processes URLs in a manner that does not adequately sanitize or validate the structure of authentication components within URLs. This allows an attacker to construct a malicious URL where the user:pass portion extends far beyond normal limits, effectively pushing the real hostname into a position that gets incorrectly interpreted during the dialog display. The vulnerability specifically affects versions prior to firefox 1.0.1 thunderbird 1.0.1 and mozilla 1.7.6, indicating this was a well-known issue that required patching in the browser security stack.
The operational impact of this vulnerability is significant as it enables man-in-the-middle attacks and phishing scenarios where attackers can deceive users into believing they are installing software from a trusted source. When users see a spoofed hostname in the installation confirmation dialog, they may unknowingly proceed with installations that could compromise their systems. This creates a trust boundary violation where the user interface displays false information about the source of the installation request. The vulnerability essentially undermines the security model of these browsers by allowing attackers to manipulate the perceived authenticity of installation sources, potentially leading to malicious software installations or credential theft.
The attack vector requires the victim to interact with a maliciously crafted URL that triggers the InstallTrigger API functionality. This typically occurs when users visit compromised websites or click on malicious links that contain the specially crafted URLs. The vulnerability aligns with CWE-601 URL Redirector Abuse and maps to ATT&CK technique T1190 for exploitation of web applications. Organizations should ensure immediate patching of affected browser versions and implement network monitoring to detect suspicious URL patterns. Additional mitigations include browser security hardening measures such as disabling the InstallTrigger API for untrusted sites and implementing content security policies that restrict installation triggers from unknown sources. Regular security updates and user education about suspicious installation prompts remain critical defense measures against this class of vulnerability.