CVE-2020-6412 in Chrome
Summary
by MITRE
Insufficient validation of untrusted input in Omnibox in Google Chrome prior to 80.0.3987.87 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 • 05/10/2025
The vulnerability identified as CVE-2020-6412 represents a critical security flaw in Google Chrome's Omnibox functionality that existed prior to version 80.0.3987.87. This issue stems from inadequate validation mechanisms for untrusted input, specifically affecting how the browser handles internationalized domain names. The flaw enables malicious actors to exploit IDN homograph attacks, where visually similar characters from different character sets are used to create deceptive domain names that appear legitimate to users.
The technical implementation of this vulnerability exploits the way Chrome processes internationalized domain names using Unicode characters that resemble Latin alphabet characters. Attackers can craft domain names containing characters from scripts like Arabic, Cyrillic, or other Unicode character sets that visually mimic common web addresses. For instance, a domain name might contain a Cyrillic character that appears identical to the Latin letter 'o' in the context of web addresses. This creates a scenario where users cannot distinguish between legitimate and malicious domains through visual inspection alone.
This vulnerability operates under the Common Weakness Enumeration CWE-174, which classifies the issue as a weakness in input validation that fails to properly sanitize or validate untrusted data. The attack vector allows remote code execution through domain spoofing, where users might be tricked into visiting malicious websites that appear to be legitimate domains. The operational impact extends beyond simple phishing attempts as it can enable more sophisticated attacks including credential theft, malware distribution, and financial fraud.
The attack model aligns with techniques documented in the MITRE ATT&CK framework under the T1566 tactic for "Phishing" and T1071.004 technique for "Application Layer Protocol: DNS". The vulnerability specifically targets the user trust model within web browsers, undermining the security assumptions that users make when navigating to websites. Users are deceived by visual similarities that bypass traditional security measures, making this attack particularly dangerous as it exploits human cognitive biases rather than technical vulnerabilities alone.
Organizations should immediately update to Chrome version 80.0.3987.87 or later to mitigate this vulnerability. Additional mitigations include implementing browser security policies that enforce stricter domain validation, deploying network monitoring tools to detect suspicious domain name patterns, and conducting user awareness training on recognizing potential homograph attacks. Security teams should also consider implementing DNS filtering solutions and web application firewalls that can detect and block suspicious domain name variations. The vulnerability demonstrates the critical importance of proper internationalization handling in security-critical applications and underscores the need for comprehensive input validation mechanisms across all browser components.