CVE-2008-5019 in Firefox
Summary
by MITRE
The session restore feature in Mozilla Firefox 3.x before 3.0.4 and 2.x before 2.0.0.18 allows remote attackers to violate the same origin policy to conduct cross-site scripting (XSS) attacks and execute arbitrary JavaScript with chrome privileges via unknown vectors.
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Analysis
by VulDB Data Team • 08/20/2019
The vulnerability described in CVE-2008-5019 represents a critical security flaw in Mozilla Firefox's session restore functionality that fundamentally undermines the browser's core security model. This issue affects Firefox versions 3.x prior to 3.0.4 and 2.x prior to 2.0.0.18, where the session restore feature fails to properly enforce the same origin policy. The same origin policy serves as the cornerstone of web security by preventing scripts from one origin from accessing resources or executing code in another origin, thereby protecting users from cross-site scripting attacks. When this policy is violated, it creates a dangerous pathway for attackers to bypass security boundaries and execute malicious code with elevated privileges.
The technical implementation of this vulnerability stems from improper handling of session data restoration processes within Firefox's browser engine. During session restoration, the browser attempts to reconstruct user sessions including open tabs, windows, and their respective content. However, the flaw allows malicious web pages to inject or manipulate session data in such a way that when the browser attempts to restore the session, it inadvertently executes malicious JavaScript code with chrome privileges. Chrome privileges represent the highest level of permissions within Firefox, allowing code to access internal browser functions, modify browser interfaces, and potentially access sensitive user data. This represents a privilege escalation vulnerability where untrusted web content gains access to browser internals through the session restore mechanism.
The operational impact of this vulnerability extends beyond typical XSS attacks, as it provides attackers with the ability to execute arbitrary JavaScript code with elevated privileges that could compromise the entire browser environment. Attackers could leverage this vulnerability to steal session cookies, modify browser settings, redirect users to malicious sites, or even install malware directly through the browser. The attack vectors remain unspecified in the CVE description, which suggests the flaw may be exploitable through multiple techniques including crafted session data manipulation, malicious bookmark injection, or targeted manipulation of browser state during restoration processes. This makes the vulnerability particularly dangerous as it may be exploitable through various attack surfaces without requiring specific user interaction beyond visiting a malicious website.
The vulnerability aligns with CWE-94, which describes "Improper Control of Generation of Code" and relates to the broader category of code injection vulnerabilities where untrusted data is executed as code. From an ATT&CK framework perspective, this vulnerability maps to T1059.007 for "Command and Scripting Interpreter: JavaScript" and T1071.001 for "Application Layer Protocol: Web Protocols", as it enables attackers to execute JavaScript code through web-based attacks. Additionally, it corresponds to T1548.002 for "Abuse of Functionality: Exploitation for Privilege Escalation" as it allows privilege escalation from regular web content to chrome privileges. The security implications are severe enough that organizations should immediately implement patches and updates to affected Firefox versions, while security teams should monitor for potential exploitation attempts and consider implementing additional browser security controls such as content security policies and strict security headers to mitigate the risk of successful exploitation.
Organizations should also consider implementing network-level protections such as web application firewalls and intrusion detection systems to monitor for exploitation attempts, while security teams should conduct thorough vulnerability assessments to ensure no other similar session management flaws exist in their browser environments. The incident highlights the critical importance of proper session management and the need for rigorous security testing of browser features that handle sensitive user data and state information, particularly those that operate with elevated privileges during normal browser operations.