CVE-2008-5013 in Firefox
Summary
by MITRE
Mozilla Firefox 2.x before 2.0.0.18 and SeaMonkey 1.x before 1.1.13 do not properly check when the Flash module has been dynamically unloaded properly, which allows remote attackers to execute arbitrary code via a crafted SWF file that "dynamically unloads itself from an outside JavaScript function," which triggers an access of an expired memory address.
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Analysis
by VulDB Data Team • 08/20/2019
This vulnerability represents a critical memory safety issue affecting Mozilla Firefox versions 2.x prior to 2.0.0.18 and SeaMonkey versions 1.x prior to 1.1.13. The flaw resides in how these browsers handle the dynamic unloading of Flash plugin modules, creating a condition where memory addresses remain accessible even after the associated Flash content has been removed from memory. This memory management error constitutes a classic use-after-free vulnerability that falls under CWE-416, where a program attempts to access memory after it has been freed or deallocated. The vulnerability specifically manifests when a malicious SWF file executes a self-unloading operation triggered by an external JavaScript function, creating a scenario where the browser's Flash plugin maintains references to freed memory locations.
The technical exploitation of this vulnerability occurs through a carefully crafted SWF file that leverages the dynamic unloading capabilities of the Flash plugin to trigger memory corruption. When the Flash module is dynamically unloaded, the browser's memory management system fails to properly invalidate the references to that memory segment, allowing an attacker to manipulate the freed memory address through subsequent JavaScript operations. This creates an opportunity for arbitrary code execution because the attacker can control the contents of the memory location that was previously occupied by the Flash module, potentially overwriting critical program data or executing malicious code in the context of the browser process.
The operational impact of this vulnerability extends beyond simple code execution to encompass potential full system compromise. Attackers can leverage this flaw to bypass security restrictions and execute malicious payloads with the privileges of the browser user, potentially leading to data theft, system infiltration, or further exploitation through privilege escalation techniques. The vulnerability affects web browsers that rely on the Flash plugin for multimedia content, making it particularly dangerous in environments where users frequently visit untrusted websites. This issue aligns with ATT&CK technique T1059.007 for Command and Scripting Interpreter and T1068 for Exploitation for Privilege Escalation, as it provides a vector for executing arbitrary code and potentially escalating privileges within the browser environment.
Mitigation strategies for this vulnerability involve immediate patching of affected browser versions, as the original issue was resolved through proper memory management updates in subsequent releases. Organizations should implement browser update policies that ensure all users maintain current versions of Firefox and SeaMonkey, while also considering the deployment of additional security measures such as content filtering and sandboxing technologies. The vulnerability highlights the importance of proper memory management in browser plugins and demonstrates how seemingly isolated issues in third-party components can create significant security risks for entire browser ecosystems, emphasizing the need for comprehensive security testing of plugin interactions and memory handling procedures.