CVE-2023-32209 in Firefox
Summary
by MITRE • 06/19/2023
A maliciously crafted favicon could have led to an out of memory crash. This vulnerability affects Firefox < 113.
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Analysis
by VulDB Data Team • 06/19/2023
This vulnerability represents a critical memory management flaw in the Firefox browser's handling of favicon resources, specifically impacting versions prior to 113. The issue arises from insufficient input validation and memory allocation controls when processing maliciously crafted favicon files, creating a potential denial of service scenario that could be exploited by attackers to consume excessive system resources. The vulnerability stems from the browser's failure to properly constrain memory allocation during favicon processing, allowing an attacker to craft specially formatted favicon files that trigger unbounded memory consumption patterns within the rendering pipeline.
The technical implementation of this vulnerability involves the manipulation of favicon data structures in a way that bypasses normal resource limits imposed by the browser's memory management subsystem. When Firefox encounters a malicious favicon file, the parsing routine fails to implement proper bounds checking or memory allocation constraints, leading to progressive memory exhaustion that can ultimately result in application instability or complete crash conditions. This flaw operates at the intersection of web content processing and memory management, where the expected resource consumption for favicon handling becomes unbounded under malicious input conditions.
From an operational security perspective, this vulnerability presents a significant risk to users running affected Firefox versions, as it can be exploited through seemingly benign web content delivery. Attackers need only host a maliciously crafted favicon on a webpage or web service to potentially trigger the memory exhaustion condition across all vulnerable browser instances. The impact extends beyond simple denial of service to potential system instability, especially in environments where multiple browser tabs or applications are running concurrently, as the memory consumption can rapidly escalate and affect overall system performance.
The vulnerability aligns with CWE-129, which addresses improper validation of length or count values, and represents a specific implementation weakness where the favicon parsing routine lacks adequate input sanitization. From an ATT&CK framework perspective, this vulnerability maps to T1499.004, specifically targeting resource hijacking through denial of service attacks, while also potentially enabling subsequent exploitation techniques if combined with other vulnerabilities in the same attack chain. The flaw demonstrates how seemingly innocuous web elements like favicons can serve as entry points for more sophisticated attacks due to inadequate security controls in browser rendering engines.
Mitigation strategies should prioritize immediate patching of affected Firefox installations to version 113 or later, where memory allocation constraints and input validation have been implemented. Organizations should also consider implementing network-level protections such as content filtering rules that block suspicious favicon file types or implement browser security policies that restrict favicon processing entirely. Additionally, users should be educated about the risks of visiting untrusted websites and the importance of maintaining updated browser software to prevent exploitation of known vulnerabilities in the browser's rendering pipeline.