CVE-2017-5407 in Firefox
Summary
by MITRE
Using SVG filters that don't use the fixed point math implementation on a target iframe, a malicious page can extract pixel values from a targeted user. This can be used to extract history information and read text values across domains. This violates same-origin policy and leads to information disclosure. This vulnerability affects Firefox < 52, Firefox ESR < 45.8, Thunderbird < 52, and Thunderbird < 45.8.
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Analysis
by VulDB Data Team • 11/26/2025
The vulnerability described in CVE-2017-5407 represents a critical security flaw in Mozilla Firefox and Thunderbird browsers that exploits SVG filter implementations to bypass cross-origin security restrictions. This vulnerability specifically targets the way browsers handle fixed-point math operations within SVG filter elements, creating an unintended information disclosure channel that can be leveraged by malicious actors to extract sensitive data from targeted web pages.
The technical exploitation mechanism relies on the inconsistent implementation of fixed-point arithmetic within SVG filter processing. When a malicious page loads an iframe containing SVG filters that do not utilize the standard fixed-point math implementation, it can manipulate timing variations in pixel processing to infer information about the target content. This occurs because different pixel values produce slightly different processing times, which can be measured and analyzed to reconstruct pixel data from the target iframe. The flaw exists in the underlying graphics rendering pipeline where the browser's handling of fixed-point calculations creates observable timing differences that leak information across domain boundaries.
This vulnerability directly violates the fundamental same-origin policy that governs web security by allowing cross-domain information leakage through timing side channels. The attack vector specifically targets the rendering engine's treatment of SVG filter operations, enabling attackers to extract history information and read text values from different domains. The implications extend beyond simple data leakage as this technique can be used to build detailed profiles of user browsing behavior, potentially compromising user privacy and security. The vulnerability affects multiple Mozilla products including Firefox versions prior to 52, Firefox ESR versions prior to 45.8, Thunderbird versions prior to 52, and Thunderbird versions prior to 45.8, indicating a widespread impact across the Mozilla ecosystem.
The operational impact of this vulnerability is severe as it enables sophisticated cross-site scripting attacks that can bypass traditional security boundaries. Security researchers have classified this issue under CWE-200 (Information Exposure) and it aligns with ATT&CK techniques related to information gathering and credential access through timing attacks. The vulnerability demonstrates how seemingly innocuous graphics processing features can be weaponized to create persistent information leakage channels. Organizations using affected versions of these browsers face significant risks as attackers can use this technique to build detailed user profiles, potentially compromising sensitive information such as browsing history, personal communications, and other cross-domain data that should remain isolated. The remediation requires updating to patched versions of the affected software, as the underlying implementation issues cannot be effectively mitigated through configuration changes or workarounds.
The vulnerability represents a sophisticated example of how modern browser security models can be undermined through unexpected interactions between different subsystems. It highlights the importance of comprehensive security testing across all browser components, particularly those involving graphics processing and rendering. The attack demonstrates the need for careful consideration of side-channel vulnerabilities in graphics and rendering engines, as these components often handle sensitive data processing in ways that can create information leakage pathways. This vulnerability serves as a reminder that even specialized features like SVG filters can introduce security risks when not properly isolated from the core security model of the browser.