CVE-2011-3885 in Chrome
Summary
by MITRE
Use-after-free vulnerability in Google Chrome before 15.0.874.102 allows remote attackers to cause a denial of service or possibly have unspecified other impact via vectors related to stale Cascading Style Sheets (CSS) token-sequence data.
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Analysis
by VulDB Data Team • 11/24/2021
The vulnerability identified as CVE-2011-3885 represents a critical use-after-free flaw in Google Chrome browser versions prior to 15.0.874.102. This vulnerability falls under the Common Weakness Enumeration category CWE-416, which specifically addresses the use of freed memory conditions that can lead to unpredictable behavior and potential exploitation. The issue manifests within the browser's handling of Cascading Style Sheets CSS token-sequence data, where stale or improperly managed memory references create opportunities for malicious actors to manipulate the browser's memory management system.
The technical implementation of this vulnerability occurs when Chrome processes CSS content that contains malformed or specially crafted token sequences. During the parsing and rendering process, the browser allocates memory for CSS data structures and subsequently frees this memory when the data is no longer needed. However, under certain conditions involving stale CSS token-sequence data, the browser may attempt to access memory that has already been freed, creating a use-after-free condition. This memory access violation can occur during the rendering pipeline when the browser tries to process cached or previously parsed CSS elements that reference deallocated memory locations.
The operational impact of this vulnerability extends beyond simple denial of service scenarios, as indicated by the unspecified other impacts mentioned in the CVE description. Attackers can potentially leverage this condition to execute arbitrary code on vulnerable systems, making it a significant security risk for users. The remote exploitation capability means that malicious actors can craft web pages containing specially designed CSS content that triggers the vulnerability when loaded in a victim's browser. This creates a vector for drive-by attacks where users are compromised simply by visiting malicious websites without any additional user interaction required.
The exploitation of this vulnerability aligns with several tactics described in the MITRE ATT&CK framework, particularly those related to privilege escalation and code execution. The use-after-free condition provides attackers with a mechanism to manipulate memory contents and potentially inject malicious code into the browser process. Security researchers have noted that such vulnerabilities often serve as initial access points for more sophisticated attack chains, where the initial denial of service or code execution is followed by further exploitation attempts. The vulnerability demonstrates how seemingly benign web content processing can become a critical security concern when memory management flaws are present in browser implementations.
Organizations and users should immediately update to Chrome version 15.0.874.102 or later to remediate this vulnerability. Additionally, implementing network-level protections such as content filtering and web application firewalls can provide additional layers of defense. The vulnerability highlights the importance of regular browser updates and the need for robust memory management practices in web browser implementations. Security teams should monitor for any related exploitation attempts and consider implementing browser hardening measures that limit the potential impact of such vulnerabilities. The incident underscores the critical nature of maintaining up-to-date software and the necessity of thorough security testing, particularly for memory management components in complex software systems.