CVE-2013-5599 in Firefox
Summary
by MITRE
Use-after-free vulnerability in the nsIPresShell::GetPresContext function in the PresShell (aka presentation shell) implementation in Mozilla Firefox before 25.0, Firefox ESR 17.x before 17.0.10 and 24.x before 24.1, Thunderbird before 24.1, Thunderbird ESR 17.x before 17.0.10, and SeaMonkey before 2.22 allows remote attackers to execute arbitrary code or cause a denial of service (heap memory corruption and application crash) via vectors involving a CANVAS element, a mozTextStyle attribute, and an onresize event.
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Analysis
by VulDB Data Team • 11/25/2025
The CVE-2013-5599 vulnerability represents a critical use-after-free flaw within Mozilla Firefox's presentation shell implementation that affects multiple products including Firefox, Thunderbird, and SeaMonkey. This vulnerability stems from improper memory management in the nsIPresShell::GetPresContext function, which is part of the PresShell component responsible for rendering web content. The flaw manifests when processing specific combinations of HTML elements and attributes, particularly involving canvas elements with mozTextStyle attributes and onresize event handlers. Such vulnerabilities are classified under CWE-416 as use-after-free conditions, which occur when a program continues to reference memory after it has been freed, creating potential exploitation opportunities for malicious actors.
The technical exploitation of this vulnerability involves crafting malicious web content that triggers the specific sequence of operations leading to the use-after-free condition. Attackers can manipulate a CANVAS element with a mozTextStyle attribute and attach an onresize event handler to create a scenario where the presentation shell attempts to access freed memory locations. This manipulation results in heap memory corruption that can be leveraged to execute arbitrary code with the privileges of the affected application. The vulnerability's impact is significant as it can be triggered through web-based attacks without requiring user interaction beyond visiting a malicious website, making it particularly dangerous in phishing campaigns and drive-by download scenarios.
From an operational perspective, this vulnerability poses severe risks to end users and organizations relying on affected Mozilla products. The ability to execute arbitrary code remotely means attackers can gain full control of affected systems, potentially leading to data breaches, system compromise, and further lateral movement within networks. The heap corruption aspect also creates opportunities for denial of service attacks that can crash applications repeatedly, disrupting business operations and user productivity. According to ATT&CK framework, this vulnerability aligns with techniques involving code injection and privilege escalation, specifically targeting the application layer and leveraging memory corruption as a primary attack vector.
Organizations should prioritize immediate patching of affected systems, as Mozilla released versions 25.0, 17.0.10, and 24.1 to address this vulnerability. System administrators should implement comprehensive monitoring for suspicious web traffic and ensure all affected products are updated through proper channels. Additionally, network security controls including web application firewalls and content filtering systems can provide additional defense-in-depth measures. The vulnerability highlights the importance of memory safety practices in browser implementations and underscores the need for regular security assessments of core rendering components. Organizations should also consider implementing user education programs to recognize potentially malicious web content and maintain up-to-date security patches across all software components to prevent exploitation of similar memory corruption vulnerabilities.