CVE-2014-1563 in Firefox
Summary
by MITRE
Use-after-free vulnerability in the mozilla::DOMSVGLength::GetTearOff function in Mozilla Firefox before 32.0, Firefox ESR 31.x before 31.1, and Thunderbird 31.x before 31.1 allows remote attackers to execute arbitrary code or cause a denial of service (heap memory corruption) via an SVG animation with DOM interaction that triggers incorrect cycle collection.
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Analysis
by VulDB Data Team • 02/15/2022
The CVE-2014-1563 vulnerability represents a critical use-after-free flaw in Mozilla Firefox and Thunderbird browsers that emerged from improper memory management during SVG animation processing. This vulnerability resides within the mozilla::DOMSVGLength::GetTearOff function, which handles the manipulation of Scalable Vector Graphics elements in web applications. The flaw specifically manifests when browsers encounter SVG animations that involve DOM interactions, creating conditions where memory locations are improperly released and subsequently accessed by malicious code. The vulnerability affects multiple versions of Firefox including those before 32.0 and Firefox ESR 31.x before 31.1, along with Thunderbird 31.x before 31.1, indicating a widespread impact across the Mozilla ecosystem.
The technical exploitation of this vulnerability occurs through carefully crafted SVG animation sequences that trigger incorrect cycle collection mechanisms within the browser's garbage collector. When the DOMSVGLength::GetTearOff function processes these animations, it fails to properly manage object references, leading to a situation where memory allocated to SVG objects becomes freed while still being referenced by other components. This improper memory management creates a use-after-free condition that can be leveraged by remote attackers to execute arbitrary code or induce heap memory corruption. The vulnerability specifically exploits the interaction between SVG DOM elements and the browser's cycle collection process, where objects that should remain in memory are prematurely destroyed, creating exploitable memory states that can be manipulated for code execution.
The operational impact of CVE-2014-1563 extends beyond simple denial of service to encompass full remote code execution capabilities, making it particularly dangerous for web browsing environments. Attackers can craft malicious web pages containing SVG animations that, when rendered by vulnerable browsers, trigger the use-after-free condition and allow for arbitrary code execution with the privileges of the browser process. This vulnerability can be particularly devastating in enterprise environments where users may encounter malicious content through phishing attacks, compromised websites, or social engineering campaigns. The heap memory corruption resulting from this flaw can lead to unpredictable behavior including browser crashes, data corruption, or complete system compromise depending on the execution environment and attack vector used.
Security mitigations for this vulnerability primarily involve immediate patching of affected browser versions to the latest secure releases that contain memory management fixes for the DOMSVGLength::GetTearOff function. Organizations should implement comprehensive browser update policies that ensure all users maintain current versions of Firefox and Thunderbird. Additionally, network administrators can deploy web content filtering solutions that block access to known malicious SVG content and implement security headers that limit SVG processing capabilities. From a defensive perspective, the vulnerability aligns with ATT&CK technique T1203 (Exploitation for Client Execution) and CWE-416 (Use After Free) which emphasizes the importance of proper memory management and object lifetime handling in browser security. Regular security assessments should include verification of browser versions and patch status to prevent exploitation of this class of vulnerabilities that can lead to complete system compromise through remote code execution.