CVE-2011-3655 in Firefox
Summary
by MITRE
Mozilla Firefox 4.x through 7.0 and Thunderbird 5.0 through 7.0 perform access control without checking for use of the NoWaiverWrapper wrapper, which allows remote attackers to gain privileges via a crafted web site.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 11/26/2021
The vulnerability identified as CVE-2011-3655 represents a critical security flaw in Mozilla Firefox versions 4.0 through 7.0 and Thunderbird versions 5.0 through 7.0 that stems from inadequate access control mechanisms within the browser's security architecture. This weakness specifically targets the handling of the NoWaiverWrapper wrapper, which is a crucial component in the browser's security model designed to prevent unauthorized access to privileged operations. The flaw allows remote attackers to bypass security restrictions by crafting malicious web content that exploits the absence of proper wrapper validation during access control checks.
The technical implementation of this vulnerability resides in the browser's JavaScript engine and security sandbox mechanisms where the NoWaiverWrapper wrapper is intended to enforce strict access control policies. When the browser processes web content, it should verify that the NoWaiverWrapper is properly applied before allowing access to privileged operations or objects. However, the flaw occurs when the access control system fails to validate whether the NoWaiverWrapper is being used, creating a pathway for malicious code to escalate privileges. This issue is particularly dangerous because it operates at the core of the browser's security model, potentially allowing attackers to execute arbitrary code with elevated privileges.
The operational impact of CVE-2011-3655 is severe and far-reaching, as it enables remote code execution capabilities that can be exploited through standard web browsing activities. An attacker could craft a malicious website that, when visited by an unsuspecting user, would trigger the vulnerability and allow the attacker to gain unauthorized access to the user's system with the privileges of the browser process. This could lead to complete system compromise, data theft, or further lateral movement within a network. The vulnerability affects not just Firefox but also Thunderbird, extending the potential attack surface to email clients that process untrusted content, making it a particularly concerning flaw for enterprise environments where these applications are widely deployed.
From a cybersecurity perspective, this vulnerability aligns with CWE-284, which addresses improper access control issues, and relates to the broader category of privilege escalation attacks that fall under the ATT&CK framework's privilege escalation techniques. The flaw demonstrates a classic example of how security boundaries can be circumvented when underlying validation mechanisms are insufficiently implemented. Organizations should prioritize immediate patching of affected versions, as the vulnerability was actively exploited in the wild during its timeframe. Additional mitigations include implementing web application firewalls, deploying content security policies, and educating users about the risks of visiting untrusted websites. The vulnerability also underscores the importance of proper security architecture design and the necessity of thorough testing of access control mechanisms, particularly in complex software environments where multiple security layers must work in concert to provide effective protection.