CVE-2013-0795 in Firefox
Summary
by MITRE
The System Only Wrapper (SOW) implementation in Mozilla Firefox before 20.0, Firefox ESR 17.x before 17.0.5, Thunderbird before 17.0.5, Thunderbird ESR 17.x before 17.0.5, and SeaMonkey before 2.17 does not prevent use of the cloneNode method for cloning a protected node, which allows remote attackers to bypass the Same Origin Policy or possibly execute arbitrary JavaScript code with chrome privileges via a crafted web site.
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Analysis
by VulDB Data Team • 01/31/2018
The vulnerability described in CVE-2013-0795 represents a critical security flaw in the System Only Wrapper (SOW) implementation within Mozilla Firefox and related applications. This issue affects versions prior to Firefox 20.0, Firefox ESR 17.x before 17.0.5, Thunderbird before 17.0.5, Thunderbird ESR 17.x before 17.0.5, and SeaMonkey before 2.17. The flaw stems from insufficient protection mechanisms that should prevent unauthorized access to privileged DOM nodes, creating a pathway for attackers to circumvent fundamental web security boundaries.
The technical implementation flaw resides in how the SOW handles the cloneNode method execution. When a web page attempts to clone a protected node using cloneNode, the SOW fails to properly validate or restrict this operation, allowing the cloning of privileged elements that should remain inaccessible to regular web content. This behavior directly violates the Same Origin Policy, which is a fundamental security mechanism designed to prevent unauthorized access to resources from different origins. The vulnerability operates at the DOM level, where attackers can leverage this weakness to create copies of protected elements that contain sensitive chrome privileges.
The operational impact of this vulnerability is severe and multifaceted, potentially enabling both privilege escalation and remote code execution attacks. Attackers can craft malicious websites that exploit this flaw to bypass security restrictions and gain access to chrome-level privileges, which typically include access to browser internals, system resources, and other sensitive functionality. This escalation allows adversaries to execute arbitrary JavaScript code with elevated privileges, potentially leading to complete browser compromise, data theft, or further exploitation of the underlying system. The vulnerability's potential for remote code execution makes it particularly dangerous in the context of web-based attacks.
The security implications extend beyond simple privilege bypass, as this flaw aligns with multiple attack patterns documented in the ATT&CK framework under privilege escalation and code execution techniques. The vulnerability represents a classic case of insufficient input validation and access control enforcement, which corresponds to CWE-284, Access Control Flaws. Organizations using affected versions of these browser applications face significant risk, as the vulnerability can be exploited through standard web browsing activities without requiring any special user interaction beyond visiting a malicious website. The SOW mechanism was designed to provide a security boundary between privileged chrome code and unprivileged web content, but this implementation defect undermines that essential protection layer.
Mitigation strategies for this vulnerability involve immediate deployment of patched versions of the affected applications, as the primary fix requires updating to versions that properly implement SOW restrictions for cloneNode operations. Security administrators should also implement network-level protections such as content filtering and web application firewalls to reduce exposure to malicious sites. Browser hardening measures including disabling unnecessary JavaScript features and implementing strict content security policies can provide additional defense layers. Organizations should also consider implementing user education programs to raise awareness about the risks of visiting untrusted websites and the importance of keeping browser software updated. The vulnerability demonstrates the critical importance of maintaining up-to-date security patches and the potential consequences of running outdated software in enterprise environments.