CVE-2020-6571 in Chrome
Summary
by MITRE
Insufficient data validation in Omnibox in Google Chrome prior to 85.0.4183.83 allowed a remote attacker to perform domain spoofing via IDN homographs via a crafted domain name.
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Analysis
by VulDB Data Team • 09/22/2020
The vulnerability identified as CVE-2020-6571 represents a critical security flaw in Google Chrome's Omnibox functionality that existed prior to version 85.0.4183.83. This issue stems from inadequate data validation mechanisms that fail to properly handle internationalized domain names, creating opportunities for sophisticated phishing attacks. The vulnerability specifically targets the browser's address bar display system where domain names are processed and rendered to users, making it a prime target for cybercriminals seeking to exploit user trust in web navigation.
The technical exploitation of this vulnerability relies on IDN (Internationalized Domain Name) homograph attacks, where attackers register domain names that visually resemble legitimate websites through the use of Unicode characters from different scripts. The flaw occurs because Chrome's Omnibox does not adequately validate or normalize domain name representations before displaying them to users, allowing malicious actors to craft domain names that appear identical or nearly identical to trusted domains. This creates a scenario where users may be deceived into believing they are visiting legitimate websites when in fact they are interacting with fraudulent domains that exploit the visual similarities of international character sets.
From an operational impact perspective, this vulnerability poses significant risks to user security and privacy across numerous attack vectors. The domain spoofing capability enables attackers to conduct highly convincing phishing campaigns that can bypass traditional security measures, as users often trust the browser interface and may not notice subtle visual differences in domain names. The attack surface extends beyond simple credential theft to include financial fraud, data exfiltration, and malware distribution. Organizations relying on Chrome as their primary browser face increased risk of successful social engineering attacks, particularly in environments where users may not be adequately trained to identify such sophisticated threats.
The vulnerability aligns with CWE-1004 which addresses the weakness of insufficient data validation in user-facing interfaces, and relates to ATT&CK technique T1566.001 which covers spearphishing through social engineering. Organizations should implement immediate mitigations including mandatory browser updates to version 85.0.4183.83 or later, deployment of network monitoring solutions to detect suspicious domain activity, and enhanced user education regarding the risks of IDN homograph attacks. Additional protective measures include implementing DNS-based security solutions, deploying browser security extensions, and establishing robust incident response protocols for detecting and responding to potential exploitation attempts. The fix implemented by Google addresses the core validation issue by strengthening domain name parsing and normalization processes within the Omnibox component, ensuring that potentially misleading internationalized domain names are properly handled before display to users.