CVE-2010-1213 in Firefox
Summary
by MITRE
The importScripts Web Worker method in Mozilla Firefox 3.5.x before 3.5.11 and 3.6.x before 3.6.7, Thunderbird 3.0.x before 3.0.6 and 3.1.x before 3.1.1, and SeaMonkey before 2.0.6 does not verify that content is valid JavaScript code, which allows remote attackers to bypass the Same Origin Policy and obtain sensitive information via a crafted HTML document.
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Analysis
by VulDB Data Team • 09/21/2021
The vulnerability described in CVE-2010-1213 represents a critical security flaw in the Web Worker implementation of several Mozilla-based browsers including Firefox, Thunderbird, and SeaMonkey. This issue specifically affects the importScripts method which is used to import JavaScript files into Web Workers. The vulnerability stems from insufficient validation of imported content, creating a path for malicious actors to exploit the Same Origin Policy mechanisms that are fundamental to web security. The flaw exists in versions prior to Firefox 3.5.11 and 3.6.7, Thunderbird 3.0.6 and 3.1.1, and SeaMonkey 2.0.6, indicating a widespread impact across multiple Mozilla products.
The technical exploitation of this vulnerability occurs through the importScripts method's failure to properly validate JavaScript content before execution. When a Web Worker attempts to import scripts using importScripts, the method should verify that the content conforms to valid JavaScript syntax and semantics. However, the vulnerable implementations accepted malformed or malicious content without proper validation, allowing attackers to inject code that could bypass the browser's security model. This validation failure creates a scenario where remote attackers can craft HTML documents that, when processed by the affected browsers, enable unauthorized access to sensitive information across different origins.
The operational impact of this vulnerability is significant as it allows remote attackers to circumvent the Same Origin Policy, which is one of the core security mechanisms protecting web applications. This policy prevents scripts from one origin from accessing resources from another origin, thereby protecting users from cross-site scripting attacks and data leakage. When bypassed, attackers can potentially access cookies, local storage, and other sensitive data that should be isolated between different origins. The vulnerability particularly affects web applications that rely on Web Workers for background processing, as these workers can be manipulated to execute malicious code that accesses restricted resources.
This vulnerability aligns with CWE-20, which describes improper input validation, and represents a classic example of how insufficient validation can lead to severe security consequences. From an adversarial perspective, this flaw maps to ATT&CK technique T1059.007 for execution through web shells and T1566 for initial access via malicious web content. The vulnerability demonstrates the importance of proper input validation in security-critical components and highlights how even seemingly minor implementation flaws can have major implications for web security. Organizations using affected versions of these browsers should immediately implement patches and updates to prevent exploitation, as the vulnerability provides attackers with a straightforward method to bypass fundamental web security protections.
The remediation strategy involves updating to patched versions of the affected software, where Mozilla released updates that implemented proper validation of content imported via importScripts. Security teams should also implement network monitoring to detect potential exploitation attempts and ensure that all browser installations are kept current with security patches. Additionally, developers should be aware of the proper usage patterns for Web Workers and implement appropriate content validation mechanisms in their applications to mitigate potential impacts of similar vulnerabilities.