CVE-2015-7223 in Firefox
Summary
by MITRE
The WebExtension APIs in Mozilla Firefox before 43.0 allow remote attackers to gain privileges, and possibly obtain sensitive information or conduct cross-site scripting (XSS) attacks, via a crafted web site.
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Analysis
by VulDB Data Team • 11/18/2024
The vulnerability identified as CVE-2015-7223 represents a critical privilege escalation flaw within the WebExtension API implementation of Mozilla Firefox versions prior to 43.0. This issue resides in the browser's extension architecture where the WebExtension APIs fail to properly enforce security boundaries between privileged extension code and untrusted web content. The vulnerability stems from insufficient validation mechanisms that allow malicious websites to exploit the extension API surface to execute unauthorized operations with elevated privileges. Security researchers have classified this as a privilege escalation vulnerability that operates under CWE-264, which specifically addresses permissions, privileges, and access controls in software systems. The flaw enables attackers to bypass normal security restrictions that should prevent web pages from accessing sensitive extension APIs.
The technical exploitation of this vulnerability occurs through carefully crafted web pages that leverage the WebExtension API to gain access to functionality that should be restricted to legitimate extension code only. Attackers can craft malicious websites that utilize the extension APIs to read sensitive information from other tabs, manipulate browser state, or execute arbitrary code within the extension context. This enables sophisticated attacks including cross-site scripting scenarios where the attacker can inject malicious scripts that execute with the privileges of the extension rather than the normal user context. The vulnerability particularly affects how Firefox handles extension communication channels and API access control, creating a pathway for remote code execution through the browser's extension infrastructure. This represents a fundamental breakdown in the browser's security model where the isolation between web content and extension code becomes compromised.
The operational impact of CVE-2015-7223 extends far beyond simple information disclosure, as it enables attackers to perform comprehensive reconnaissance and establish persistent access to user systems. Successful exploitation can lead to complete browser compromise where attackers gain the ability to monitor user activity, steal session cookies, intercept communications, and potentially escalate privileges to the underlying operating system level. The vulnerability affects not only individual user data but also creates opportunities for large-scale attacks where malicious websites can target multiple Firefox users simultaneously. Organizations relying on Firefox for business operations face significant risk as this vulnerability can be exploited through social engineering campaigns, drive-by downloads, or compromised websites. The attack surface is particularly concerning given that WebExtensions are designed to be powerful and flexible, providing extensive access to browser functionality that makes this type of privilege escalation particularly dangerous.
Mitigation strategies for CVE-2015-7223 center on immediate browser updates to version 43.0 or later where Mozilla has implemented proper API access controls and privilege boundaries. System administrators should enforce mandatory browser updates through enterprise management tools and disable unnecessary extension permissions to reduce the attack surface. Users should be educated about the risks of visiting untrusted websites and the importance of keeping browsers updated. Network security measures including web proxies and content filtering systems can help detect and block malicious websites that attempt to exploit this vulnerability. The implementation of browser hardening techniques such as disabling unnecessary extension APIs, implementing strict content security policies, and using security extensions like NoScript can provide additional layers of protection. Organizations should also consider implementing monitoring solutions that can detect anomalous extension behavior patterns that may indicate exploitation attempts. This vulnerability highlights the importance of proper API design and access control implementation in browser security architectures, aligning with ATT&CK technique T1059.007 for execution through web-based attacks and T1071.001 for application layer protocols in network communications.