CVE-2011-3654 in Firefox
Summary
by MITRE
The browser engine in Mozilla Firefox before 8.0 and Thunderbird before 8.0 does not properly handle links from SVG mpath elements to non-SVG elements, which allows remote attackers to cause a denial of service (memory corruption and application crash) or possibly execute arbitrary code via unspecified vectors.
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Analysis
by VulDB Data Team • 11/26/2021
The vulnerability identified as CVE-2011-3654 represents a critical flaw in the browser engine of Mozilla Firefox and Thunderbird applications prior to version 8.0. This issue stems from improper handling of hyperlinks within Scalable Vector Graphics mpath elements that reference non-SVG content types. The flaw exists in the way these applications process cross-element references, creating potential attack vectors that could be exploited by malicious actors to compromise system integrity and availability.
The technical implementation of this vulnerability involves the browser engine's failure to properly validate and sanitize link references originating from SVG mpath elements. When these elements attempt to establish connections to non-SVG content, the application's parsing mechanism encounters unexpected data structures that trigger memory corruption patterns. This memory handling error manifests as application crashes or, in more severe cases, arbitrary code execution capabilities. The vulnerability's classification aligns with CWE-121, which addresses stack-based buffer overflow conditions, and CWE-122, concerning heap-based buffer overflow scenarios, as the memory corruption occurs during element processing and reference resolution.
The operational impact of this vulnerability extends beyond simple denial of service conditions to encompass potential remote code execution threats. Attackers can craft malicious web pages or email content that exploits the mpath element linking mechanism to trigger memory corruption within the browser engine. This creates opportunities for persistent attacks where adversaries can leverage the vulnerability to gain unauthorized access to affected systems. The attack surface is particularly concerning given that the flaw affects both Firefox web browser and Thunderbird email client applications, which are widely deployed across enterprise and consumer environments.
From a threat modeling perspective, this vulnerability maps to several ATT&CK techniques including T1203, which covers exploitation of remote services, and T1059, concerning command and script injection. The attack chain typically involves delivery of malicious content through web browsing or email interactions, followed by exploitation of the memory corruption to execute malicious payloads. Organizations should consider implementing network-based protections such as web application firewalls and email filtering solutions to mitigate initial access vectors. The vulnerability's remediation requires immediate application of security patches to Firefox version 8.0 and Thunderbird version 8.0, as these releases contain the necessary fixes to properly handle SVG element references and prevent memory corruption scenarios.
The broader implications of this vulnerability highlight the complexity of modern browser security architectures and the challenges posed by cross-technology element references. SVG processing within web browsers represents a sophisticated feature set that requires careful validation to prevent exploitation of underlying memory management systems. Security practitioners should recognize that vulnerabilities of this nature often emerge from the intersection of multiple technologies and can be particularly challenging to detect and remediate. The incident underscores the importance of continuous security monitoring and prompt patch management processes to protect against similar flaws in other browser engine components. Organizations must maintain comprehensive vulnerability assessment procedures that include testing for similar cross-element reference issues in other web technologies and applications.