CVE-2006-1738 in Thunderbird
Summary
by MITRE
Unspecified vulnerability in Mozilla Firefox and Thunderbird 1.x before 1.5 and 1.0.x before 1.0.8, Mozilla Suite before 1.7.13, and SeaMonkey before 1.0 allows remote attackers to cause a denial of service (crash) by changing the (1) -moz-grid and (2) -moz-grid-group display styles.
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Analysis
by VulDB Data Team • 01/20/2025
This vulnerability affects multiple Mozilla-based applications including Firefox, Thunderbird, the Mozilla Suite, and SeaMonkey, specifically targeting versions prior to their respective security patches. The issue stems from improper handling of CSS display properties, particularly the -moz-grid and -moz-grid-group styles that are Mozilla-specific extensions for implementing grid layout functionality. These display styles are part of the proprietary Mozilla CSS extensions that provide advanced layout capabilities beyond standard web specifications.
The technical flaw manifests when remote attackers manipulate the CSS styling of web content by altering the -moz-grid and -moz-grid-group display properties. This manipulation causes the browser rendering engine to encounter unexpected conditions during the layout calculation process, leading to memory corruption or invalid state transitions within the browser's CSS processing subsystem. The vulnerability operates at the rendering engine level where CSS properties are parsed, processed, and translated into visual layout elements, making it particularly dangerous as it can be triggered through normal web browsing activities without requiring any special privileges or user interaction beyond visiting a malicious website.
The operational impact of this vulnerability is significant as it enables remote attackers to perform denial of service attacks against targeted systems. When exploited, the vulnerability causes the affected browser applications to crash and terminate unexpectedly, effectively rendering the browser unusable for the duration of the attack. This creates a persistent disruption to user productivity and can be particularly problematic in enterprise environments where browser stability is critical for business operations. The attack vector requires only that a user visit a malicious webpage containing crafted CSS content, making it easily exploitable through various means including phishing campaigns, compromised websites, or malicious advertisements.
Mitigation strategies for this vulnerability include immediate deployment of security patches released by Mozilla for all affected versions, which typically involve fixing the CSS parsing logic and adding proper validation checks for the problematic display properties. Organizations should also implement web content filtering solutions that can detect and block malicious CSS content, particularly focusing on Mozilla-specific CSS extensions. From a defensive perspective, this vulnerability aligns with attack techniques categorized under the MITRE ATT&CK framework within the T1211 - Exploitation for Defense Evasion and T1499 - Endpoint Denial of Service categories. The vulnerability demonstrates the importance of proper input validation and memory safety practices in browser rendering engines, as classified under CWE-129 in the Common Weakness Enumeration catalog, specifically addressing improper validation of input data leading to memory corruption. System administrators should also consider implementing browser hardening measures such as disabling unnecessary CSS features, using security-focused browser configurations, and maintaining comprehensive monitoring for unusual browser crash patterns that might indicate exploitation attempts.