CVE-2012-4191 in Firefox
Summary
by MITRE
The mozilla::net::FailDelayManager::Lookup function in the WebSockets implementation in Mozilla Firefox before 16.0.1, Thunderbird before 16.0.1, and SeaMonkey before 2.13.1 allows remote attackers to cause a denial of service (memory corruption and application crash) or possibly execute arbitrary code via unspecified vectors.
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Analysis
by VulDB Data Team • 04/18/2021
The vulnerability identified as CVE-2012-4191 represents a critical memory corruption flaw within the WebSockets implementation of Mozilla's browser products. This issue affects Firefox versions prior to 16.0.1, Thunderbird versions before 16.0.1, and SeaMonkey versions before 2.13.1, demonstrating the widespread impact across Mozilla's product ecosystem. The flaw resides specifically within the mozilla::net::FailDelayManager::Lookup function, which handles the management of connection failure delays in WebSocket communications. This function serves as a critical component in maintaining stable network connections and managing retry mechanisms when network failures occur.
The technical nature of this vulnerability stems from improper memory handling within the WebSocket failure delay management system. When the Lookup function processes connection failure scenarios, it fails to properly validate or manage memory allocations and deallocations, creating conditions where attacker-controlled input can trigger memory corruption. This memory corruption manifests as application crashes during normal operation or potentially as more severe conditions that could allow arbitrary code execution. The unspecified vectors indicate that multiple attack pathways exist, making the vulnerability particularly dangerous as it could be exploited through various network communication scenarios.
From an operational perspective, this vulnerability presents significant risk to users who engage in WebSocket-based web applications, which became increasingly common in web development around that time period. The potential for remote code execution means that attackers could compromise user systems simply by having them visit malicious websites or interact with compromised web services that utilize WebSockets. The denial of service component alone would render applications unusable, causing productivity losses and potentially exposing sensitive data through application crashes. Organizations relying on these browser products for business operations faced substantial risk, as the vulnerability could be exploited through standard web browsing activities without requiring specialized knowledge or tools from attackers.
The flaw aligns with CWE-125, which describes out-of-bounds read vulnerabilities, and potentially CWE-787, which covers out-of-bounds write conditions, both of which are common in memory management errors within network protocol implementations. From an attacker's perspective, this vulnerability maps to multiple ATT&CK techniques including T1059 for command and control through compromised applications, T1499 for network disruption, and potentially T1071 for application layer protocol usage. The vulnerability's impact extends beyond individual user systems to enterprise environments where these browsers are widely deployed, making it a critical target for threat actors seeking to establish persistent access or cause operational disruption. Organizations should prioritize immediate patching of affected versions and implement network monitoring to detect potential exploitation attempts, as the vulnerability's remote nature makes it particularly attractive for automated attack campaigns.