CVE-2013-1675 in Firefox
Summary
by MITRE
Mozilla Firefox before 21.0, Firefox ESR 17.x before 17.0.6, Thunderbird before 17.0.6, and Thunderbird ESR 17.x before 17.0.6 do not properly initialize data structures for the nsDOMSVGZoomEvent::mPreviousScale and nsDOMSVGZoomEvent::mNewScale functions, which allows remote attackers to obtain sensitive information from process memory via a crafted web site.
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Analysis
by VulDB Data Team • 04/22/2026
This vulnerability represents a classic information disclosure flaw in Mozilla's browser and email client software families. The issue stems from improper initialization of data structures within the SVG zoom event handling mechanism, specifically affecting the mPreviousScale and mNewScale member variables in the nsDOMSVGZoomEvent class. When processing crafted web content containing SVG elements with zoom events, the application fails to properly initialize these memory locations before use, potentially leaving sensitive data from adjacent memory regions accessible to attackers. This type of vulnerability falls under the CWE-128 category of "Wrap or Overflow" and represents a memory safety issue that can lead to information leakage through uninitialized memory access patterns.
The technical exploitation of this vulnerability occurs when a malicious website presents SVG content that triggers the problematic code path within the browser's rendering engine. The uninitialized variables contain data that was previously stored in memory locations, potentially including cryptographic keys, session tokens, or other sensitive information from the process heap. Attackers can leverage this to construct a memory disclosure attack that can be used as a stepping stone for more sophisticated exploitation techniques. The vulnerability is particularly concerning because it operates at the browser level where it can access a wide range of sensitive data that applications and users have stored in memory.
The operational impact of this vulnerability extends beyond simple information disclosure, as it provides attackers with a means to gather intelligence about the target system and user sessions. In the context of web browser security, such information leaks can be combined with other vulnerabilities to perform advanced attacks including session hijacking, credential theft, or privilege escalation. The attack vector is particularly dangerous because it requires no user interaction beyond visiting a malicious website, making it suitable for drive-by download scenarios. From an attack framework perspective, this vulnerability aligns with techniques described in the attack pattern taxonomy under the category of information gathering and reconnaissance activities.
Mitigation strategies for this vulnerability focus primarily on immediate patching of affected software versions. Users should upgrade to Firefox 21.0 or later, Thunderbird 17.0.6 or later, and their respective ESR versions to ensure proper initialization of the affected data structures. Additionally, administrators should implement network-level protections such as web application firewalls that can detect and block known malicious SVG content patterns. The vulnerability demonstrates the importance of proper memory initialization practices in security-critical software components and highlights the need for comprehensive testing of edge cases in browser rendering engines. Security professionals should monitor for exploitation attempts and implement logging to detect unusual memory access patterns that might indicate exploitation of similar uninitialized memory issues.