CVE-2009-1307 in Firefox
Summary
by MITRE
The view-source: URI implementation in Mozilla Firefox before 3.0.9, Thunderbird, and SeaMonkey does not properly implement the Same Origin Policy, which allows remote attackers to (1) bypass crossdomain.xml restrictions and connect to arbitrary web sites via a Flash file; (2) read, create, or modify Local Shared Objects via a Flash file; or (3) bypass unspecified restrictions and render content via vectors involving a jar: URI.
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Analysis
by VulDB Data Team • 09/02/2019
The vulnerability described in CVE-2009-1307 represents a critical security flaw in the view-source URI implementation across multiple Mozilla-based applications including Firefox versions prior to 3.0.9, Thunderbird, and SeaMonkey. This weakness fundamentally undermines the browser's security model by failing to properly enforce the Same Origin Policy, a cornerstone of web security that prevents unauthorized access between different domains. The Same Origin Policy, classified under CWE-16, is designed to isolate web content from different origins to prevent malicious actors from exploiting cross-origin access patterns. When this policy is improperly implemented, it creates dangerous attack vectors that can be leveraged by remote adversaries to bypass fundamental security controls.
The technical flaw manifests specifically in how these applications handle view-source URIs, which are intended to display the source code of web pages. However, the implementation fails to properly validate origin restrictions when processing Flash content, creating opportunities for attackers to exploit this weakness through malicious Flash files. The vulnerability enables attackers to bypass crossdomain.xml restrictions, which are XML files that define which domains can access resources on a server. This bypass allows attackers to establish connections to arbitrary web sites that would normally be restricted, effectively circumventing the security boundaries that protect users from unauthorized network access. The weakness also permits manipulation of Local Shared Objects, which are Flash-specific storage mechanisms that can persist data across sessions and potentially store sensitive information.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass comprehensive data exfiltration and manipulation capabilities. Attackers can read, create, or modify Local Shared Objects through Flash files, potentially accessing sensitive user data or modifying browser behavior in persistent ways. The ability to bypass unspecified restrictions and render content via jar: URI vectors represents an additional attack surface that could be exploited for more sophisticated attacks including cross-site scripting or data injection. According to ATT&CK framework, this vulnerability maps to multiple techniques including T1059 for execution through Flash content and T1566 for social engineering via malicious content delivery. The jar: URI exploitation capability particularly aligns with T1071 for application layer protocols and T1213 for data from information repositories.
The remediation strategy for CVE-2009-1307 requires immediate patching of affected Mozilla applications to version 3.0.9 or later, which contains the necessary fixes to properly implement the Same Origin Policy for view-source URIs. Organizations should also implement network monitoring to detect suspicious crossdomain.xml bypass attempts and Local Shared Object manipulations. Security teams should consider implementing content security policies and restricting Flash plugin usage where possible. The vulnerability demonstrates the critical importance of proper URI handling and origin validation in web browsers, as even seemingly benign features like view-source can become attack vectors when security controls are improperly implemented. This weakness also underscores the need for comprehensive security testing of all URI processing mechanisms and the importance of maintaining up-to-date security patches across all browser applications.