CVE-2013-0780 in Firefox
Summary
by MITRE
Use-after-free vulnerability in the nsOverflowContinuationTracker::Finish function in Mozilla Firefox before 19.0, Firefox ESR 17.x before 17.0.3, Thunderbird before 17.0.3, Thunderbird ESR 17.x before 17.0.3, and SeaMonkey before 2.16 allows remote attackers to execute arbitrary code or cause a denial of service (heap memory corruption) via a crafted document that uses Cascading Style Sheets (CSS) -moz-column-* properties.
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Analysis
by VulDB Data Team • 05/05/2021
This vulnerability represents a critical use-after-free flaw in Mozilla's browser rendering engine that affects multiple products including Firefox, Thunderbird, and SeaMonkey. The issue occurs within the nsOverflowContinuationTracker::Finish function which handles CSS layout calculations for documents containing specific -moz-column-* properties. These CSS properties are used to create multi-column layouts in web content, but when improperly handled during document processing, they trigger memory corruption conditions that can be exploited remotely. The vulnerability stems from improper memory management where freed memory locations are accessed after being deallocated, creating opportunities for attackers to manipulate heap memory structures and potentially execute arbitrary code.
The technical exploitation of this vulnerability requires crafting a malicious HTML document containing specially constructed CSS -moz-column-* properties that trigger the specific code path in the nsOverflowContinuationTracker::Finish function. When the browser processes such a document, the memory management system attempts to free certain objects while simultaneously accessing them in a manner that creates a use-after-free condition. This heap corruption can manifest in various ways including memory corruption that allows attackers to control program execution flow or cause denial of service through application crashes. The vulnerability is particularly dangerous because it operates within the browser's core rendering engine and can be triggered through normal web browsing activities without requiring special privileges or user interaction beyond visiting a malicious website.
From an operational perspective, this vulnerability presents significant risk to users of affected versions as it allows remote code execution capabilities that can be leveraged for full system compromise. The attack vector requires only a malicious webpage containing crafted CSS content, making it highly exploitable in real-world scenarios. Security researchers have classified this vulnerability as high severity due to its remote exploitability and potential for privilege escalation. The impact extends beyond individual user systems to enterprise environments where browser-based attacks are common attack vectors. Organizations running affected versions face potential data breaches, system compromises, and loss of sensitive information when users visit malicious websites or open compromised email messages containing the exploit.
Organizations should prioritize immediate patching of all affected products including Firefox 19.0 and later, Firefox ESR 17.0.3 and later, Thunderbird 17.0.3 and later, Thunderbird ESR 17.0.3 and later, and SeaMonkey 2.16 and later. System administrators should implement network-based protections such as web application firewalls and content filtering solutions that can detect and block malicious CSS content. Security monitoring should include detection of unusual memory access patterns and heap corruption indicators in browser processes. The vulnerability aligns with CWE-416 which describes use-after-free conditions, and represents a technique commonly seen in the attack patterns documented in the ATT&CK framework under the software exploitation category. Regular security updates and patch management processes should be enforced to prevent exploitation of similar memory corruption vulnerabilities that may be discovered in the future.