CVE-2011-3658 in Firefox
Summary
by MITRE
The SVG implementation in Mozilla Firefox 8.0, Thunderbird 8.0, and SeaMonkey 2.5 does not properly interact with DOMAttrModified event handlers, which allows remote attackers to cause a denial of service (out-of-bounds memory access) or possibly have unspecified other impact via vectors involving removal of SVG elements.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 06/09/2025
The vulnerability described in CVE-2011-3658 represents a critical flaw in the Scalable Vector Graphics implementation within Mozilla Firefox 8.0 Thunderbird 8.0 and SeaMonkey 2.5 browsers. This issue stems from improper handling of DOMAttrModified event handlers during SVG element manipulation processes. The flaw manifests when attackers exploit the interaction between SVG rendering and DOM event processing mechanisms, creating a scenario where maliciously crafted SVG content can trigger unexpected behavior in the browser's memory management systems. The vulnerability falls under the category of memory corruption issues that can lead to unpredictable system states and potentially enable more sophisticated attack vectors beyond simple denial of service.
The technical root cause of this vulnerability lies in the improper synchronization between SVG element removal operations and DOM event handler execution contexts. When SVG elements are removed from the document object model, the browser's event system attempts to notify registered DOMAttrModified listeners about attribute changes. However, the Firefox implementation fails to properly validate the state of memory structures during this notification process, particularly when dealing with the removal of elements that may have been previously modified. This mismanagement creates opportunities for out-of-bounds memory access patterns where the event handlers attempt to reference memory locations that have already been freed or are otherwise inaccessible. The vulnerability specifically impacts the interaction between the SVG rendering engine and the DOM event system, creating a race condition or memory consistency issue that can be exploited remotely.
The operational impact of this vulnerability extends beyond simple denial of service scenarios to potentially enable more serious security consequences. Remote attackers can leverage this flaw to crash browser processes through controlled memory access violations, effectively preventing legitimate users from accessing web content. In some configurations or under specific conditions, the out-of-bounds memory access patterns could potentially be exploited to execute arbitrary code within the browser context, though this requires additional attack surface exploitation. The vulnerability affects all versions of the affected Mozilla products mentioned, making it particularly concerning for organizations that have not yet updated their browser installations. The attack vector requires the victim to visit a malicious web page containing crafted SVG content, making it a client-side exploitation scenario that can bypass many traditional network-based security controls.
Mitigation strategies for CVE-2011-3658 primarily focus on immediate product updates and browser version management. Organizations should prioritize updating Firefox Thunderbird and SeaMonkey installations to versions that contain patches addressing this vulnerability. The fix typically involves implementing proper memory validation checks during DOMAttrModified event processing and ensuring that SVG element removal operations do not trigger invalid memory references. Security teams should also consider implementing web content filtering solutions that can detect and block potentially malicious SVG content, particularly in environments where browser updates cannot be immediately deployed. Additionally, users should be educated about the risks of visiting untrusted websites and the importance of keeping their browser software up to date. From a compliance perspective, this vulnerability aligns with CWE-125 out-of-bounds read conditions and CWE-787 out-of-bounds write conditions, representing memory safety issues that are commonly addressed through secure coding practices and input validation mechanisms. The vulnerability also maps to ATT&CK technique T1203 legitimate credentials for browser-based attacks that leverage client-side flaws to compromise user systems.