CVE-2010-4577 in Chrome
Summary
by MITRE
The CSSParser::parseFontFaceSrc function in WebCore/css/CSSParser.cpp in WebKit, as used in Google Chrome before 8.0.552.224, Chrome OS before 8.0.552.343, webkitgtk before 1.2.6, and other products does not properly parse Cascading Style Sheets (CSS) token sequences, which allows remote attackers to cause a denial of service (out-of-bounds read) via a crafted local font, related to "Type Confusion."
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Analysis
by VulDB Data Team • 01/21/2025
The vulnerability identified as CVE-2010-4577 represents a critical out-of-bounds read flaw within the WebKit rendering engine's CSS parsing functionality. This issue affects the CSSParser::parseFontFaceSrc function located in WebCore/css/CSSParser.cpp, which is responsible for processing CSS font face declarations and local font references. The flaw manifests when the parser encounters malformed CSS token sequences in font-related CSS declarations, specifically in how it handles local font resources. The vulnerability stems from improper validation and parsing of CSS font face source specifications, creating a type confusion scenario that leads to memory access violations.
The technical implementation of this vulnerability exploits the CSS parsing logic's failure to properly validate input parameters when processing font face declarations. When a maliciously crafted CSS file containing specially constructed local font references is processed by the affected WebKit-based browsers, the parser's internal state becomes corrupted due to incorrect type handling during token sequence parsing. This type confusion results in the parser attempting to read memory locations beyond the allocated buffer boundaries, leading to an out-of-bounds read condition. The flaw is particularly dangerous because it can be triggered through web content, making it exploitable in remote attack scenarios where attackers can craft malicious CSS files or web pages that contain the vulnerable font face declarations.
The operational impact of this vulnerability extends beyond simple denial of service, as it can be leveraged by remote attackers to potentially execute arbitrary code or cause browser crashes. When the affected browsers process malicious CSS content containing crafted local font declarations, the out-of-bounds read can lead to memory corruption that may be exploited to redirect execution flow or cause system instability. This vulnerability affects multiple high-profile products including Google Chrome versions prior to 8.0.552.224, Chrome OS versions before 8.0.552.343, and webkitgtk versions before 1.2.6, demonstrating the widespread nature of the affected codebase. The vulnerability aligns with CWE-129, which describes improper validation of array indices, and can be categorized under ATT&CK technique T1059.001 for command and scripting interpreter usage in exploitation contexts.
Mitigation strategies for this vulnerability require immediate patching of affected software versions, as the flaw exists in core parsing functionality that cannot be effectively bypassed through configuration changes. System administrators should prioritize updating Chrome browsers to version 8.0.552.224 or later, Chrome OS to version 8.0.552.343 or later, and webkitgtk to version 1.2.6 or later. Additionally, organizations should implement network-level controls to filter potentially malicious CSS content and consider deploying web application firewalls that can detect and block suspicious font-related CSS patterns. The vulnerability highlights the importance of robust input validation in parsing components and underscores the need for comprehensive memory safety testing in browser rendering engines. Security monitoring should focus on detecting unusual browser behavior or crashes that might indicate exploitation attempts, particularly when processing web content with complex CSS font declarations.