CVE-2011-2826 in Chrome
Summary
by MITRE
Google Chrome before 13.0.782.215 allows remote attackers to bypass the Same Origin Policy via vectors related to empty origins.
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Analysis
by VulDB Data Team • 11/18/2021
The vulnerability identified as CVE-2011-2826 represents a critical security flaw in Google Chrome browsers prior to version 13.0.782.215 that undermines the fundamental Same Origin Policy mechanism. This policy serves as a cornerstone of web security by preventing scripts from one origin from accessing resources or data from another origin, thereby protecting users from cross-site scripting attacks and data theft. The flaw specifically exploits how Chrome handled empty origins in certain web requests, creating a pathway for malicious actors to circumvent these essential security boundaries. The vulnerability demonstrates a classic example of insufficient input validation and origin checking mechanisms that are critical for maintaining web application security.
Technical exploitation of this vulnerability occurs when Chrome encounters web requests or responses that contain empty origin values, which should normally be rejected or properly validated according to web standards. The browser fails to adequately enforce origin checking when dealing with these empty origins, allowing attackers to craft malicious web content or manipulate browser behavior to access resources that should be restricted to specific origins. This issue stems from how Chrome processes and validates the Origin header in HTTP requests, particularly when that header contains empty or malformed values that do not conform to standard web security protocols. The flaw essentially creates a loophole where the browser's security model can be bypassed through carefully constructed requests that exploit the handling of these edge cases.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it fundamentally weakens the security model that web browsers rely upon for user protection. Attackers could potentially exploit this weakness to perform cross-site scripting attacks, access sensitive user data, or manipulate web applications in ways that were previously prevented by the Same Origin Policy. This vulnerability directly impacts web application security by undermining the isolation between different web origins, potentially allowing attackers to steal session cookies, access private data, or perform unauthorized actions on behalf of users. The consequences are particularly severe in environments where users browse untrusted websites or where web applications handle sensitive information, as the vulnerability could be leveraged to compromise entire user sessions and data repositories.
Mitigation strategies for this vulnerability require immediate browser updates to the patched version 13.0.782.215 or later, which properly implements origin validation for empty origins. Organizations should also consider implementing additional security measures such as content security policies, strict transport security headers, and regular security audits of web applications. The vulnerability highlights the importance of comprehensive input validation and proper security boundary enforcement in web browsers, aligning with CWE category 284 which addresses improper access control and CWE 345 which covers insufficient input validation. From an attack framework perspective, this vulnerability would be classified under the privilege escalation and information disclosure techniques in the ATT&CK methodology, specifically targeting the browser exploitation phase where adversaries attempt to bypass security controls and access restricted resources.