CVE-2016-2825 in Firefox
Summary
by MITRE
Mozilla Firefox before 47.0 allows remote attackers to bypass the Same Origin Policy and modify the location.host property via an invalid data: URL.
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Analysis
by VulDB Data Team • 08/23/2022
The vulnerability identified as CVE-2016-2825 represents a critical security flaw in Mozilla Firefox versions prior to 47.0 that fundamentally undermines the browser's core security model. This issue allows remote attackers to circumvent the same origin policy, a fundamental web security mechanism that prevents malicious websites from accessing or modifying resources from different origins. The vulnerability specifically manifests through the manipulation of data: URLs, which are designed to embed small amounts of data directly into the URI scheme. When Firefox processes an invalid data: URL, it fails to properly validate the host property, enabling attackers to manipulate this critical security element from external sources.
The technical exploitation of this vulnerability occurs through the improper handling of data: URLs within Firefox's security framework. The same origin policy relies on strict enforcement of origin boundaries, which include the scheme, host, and port components of a URL. In this case, the flaw allows an attacker to craft a malicious data: URL that bypasses these security checks, effectively granting unauthorized access to modify the location.host property. This represents a direct violation of web security principles and enables attackers to potentially perform cross-origin resource manipulation, session hijacking, or other malicious activities that should be prevented by the browser's security model.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it provides attackers with the ability to manipulate browser behavior in ways that could compromise user data and system integrity. When an attacker successfully exploits this flaw, they can effectively bypass security boundaries that protect users from malicious websites, potentially allowing them to access sensitive information, modify web page content, or redirect users to malicious destinations. The vulnerability is particularly concerning because it affects the fundamental security architecture of the browser, making it difficult for users to distinguish between legitimate and malicious content. This type of vulnerability directly relates to CWE-284, which addresses improper access control, and aligns with ATT&CK technique T1059, specifically focusing on the manipulation of browser security features.
Mitigation strategies for this vulnerability require immediate patching of affected Firefox versions to 47.0 or later, where Mozilla has implemented proper validation of data: URLs and strengthened the enforcement of same origin policy boundaries. Organizations should also implement comprehensive browser security policies that include regular security updates, monitoring for suspicious URL patterns, and user education about the risks of visiting untrusted websites. Network administrators should consider implementing web application firewalls and content filtering solutions that can detect and block malicious data: URL patterns. Additionally, security teams should conduct regular vulnerability assessments focusing on browser security configurations and monitor for any attempts to exploit this specific flaw. The remediation process should include verification that all affected systems have been properly updated and that the browser's security model is functioning correctly, as this vulnerability represents a critical threat to web application security and user privacy.