CVE-2020-6560 in Chrome
Summary
by MITRE
Insufficient policy enforcement in autofill in Google Chrome prior to 85.0.4183.83 allowed a remote attacker to leak cross-origin data via a crafted HTML page.
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Analysis
by VulDB Data Team • 09/22/2020
The vulnerability identified as CVE-2020-6560 represents a critical security flaw in Google Chrome's autofill functionality that existed prior to version 85.0.4183.83. This issue stems from inadequate policy enforcement mechanisms within the browser's autofill system, creating a pathway for malicious actors to exploit cross-origin data leakage. The vulnerability specifically targets the browser's handling of autofill data when processing crafted HTML pages, potentially exposing sensitive information across different origins. The flaw demonstrates a fundamental weakness in Chrome's security model where proper origin isolation and data protection measures were insufficiently implemented within the autofill component.
Technical exploitation of this vulnerability relies on the browser's failure to properly enforce security boundaries when processing autofill-related HTML elements. Attackers can craft malicious web pages that leverage the autofill system to access and exfiltrate data from different origins without proper authorization. The vulnerability occurs during the processing of HTML elements that trigger autofill behavior, where the browser's policy enforcement mechanisms fail to adequately validate or restrict cross-origin data access. This allows a remote attacker to potentially gather sensitive information such as form data, user credentials, or other autofill-relevant information from different websites. The technical implementation involves the manipulation of HTML attributes and elements that interact with Chrome's autofill database, bypassing expected security checks that should prevent such cross-origin information leakage.
The operational impact of this vulnerability extends beyond simple data leakage, as it represents a significant breach in browser security architecture that could enable more sophisticated attacks. An attacker could potentially combine this vulnerability with other techniques to conduct cross-site scripting attacks, credential theft, or information gathering operations across multiple domains. The risk is particularly elevated in environments where users interact with multiple websites that utilize autofill functionality, as the attack surface expands beyond individual sites. This vulnerability undermines the fundamental security principle of origin isolation that browsers enforce to protect user privacy and data integrity. The impact is amplified by Chrome's widespread usage and the automatic nature of autofill functionality, which means users may unknowingly trigger the vulnerability during routine browsing activities.
Mitigation strategies for CVE-2020-6560 primarily focus on updating to Chrome version 85.0.4183.83 or later, which includes the necessary security patches to address the insufficient policy enforcement. Organizations should implement comprehensive browser update policies to ensure all systems are running patched versions of Chrome. Security administrators should also consider monitoring for suspicious autofill-related activities and implementing additional security layers such as content security policies that restrict cross-origin resource access. The vulnerability aligns with CWE-693 - Protection Mechanism Failure, which specifically addresses situations where security mechanisms fail to provide proper protection. From an ATT&CK framework perspective, this vulnerability maps to T1566 - Phishing and potentially T1071.004 - Application Layer Protocol: DNS, as attackers may use the leaked information for further exploitation. Network administrators should also consider implementing web application firewalls and monitoring solutions that can detect unusual patterns of cross-origin data access that may indicate exploitation attempts.