CVE-2019-13659 in Chrome
Summary
by MITRE
IDN spoofing in Omnibox in Google Chrome prior to 77.0.3865.75 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 • 11/26/2019
The vulnerability identified as CVE-2019-13659 represents a critical identity spoofing flaw in Google Chrome's Omnibox functionality that existed prior to version 77.0.3865.75. This issue stems from the browser's handling of internationalized domain names that employ homographic characters, creating a scenario where malicious actors can exploit visual similarities between Latin and non-Latin characters to deceive users into believing they are visiting legitimate websites while actually navigating to attacker-controlled domains. The vulnerability specifically affects the browser's address bar rendering and validation mechanisms, which fail to properly distinguish between visually identical or similar characters from different character sets, including the use of homoglyphs that appear identical or nearly identical to users.
The technical implementation of this vulnerability occurs within Chrome's URL parsing and display logic where internationalized domain names containing characters from multiple scripts are processed without adequate validation or display sanitization. Attackers can craft domain names using Unicode characters that visually resemble legitimate domain names but contain non-Latin characters such as Cyrillic or Arabic script equivalents that appear identical to Latin characters in the browser's address bar. This allows for the creation of deceptive URLs where the visual representation of the domain name matches that of a trusted entity, enabling phishing attacks that bypass traditional security measures designed to detect malicious URLs. The flaw operates at the presentation layer of the browser, making it particularly dangerous as users cannot distinguish between legitimate and malicious domains through visual inspection alone.
The operational impact of this vulnerability extends beyond simple phishing attacks to encompass a wide range of security threats that can compromise user trust and system integrity. Users operating Chrome versions prior to 77.0.3865.75 face significant risk when browsing the internet, particularly when accessing financial services, email accounts, or other sensitive online resources where domain verification is critical. The vulnerability can be exploited across multiple attack vectors including malicious websites, email attachments, and social engineering campaigns where attackers leverage the visual deception to gain unauthorized access to user credentials, personal information, or financial assets. This issue directly violates security principles related to user authentication and trust establishment, as it undermines the fundamental assumption that URL display represents accurate domain information.
Mitigation strategies for this vulnerability require immediate browser updates to version 77.0.3865.75 or later, which implements proper internationalized domain name validation and display mechanisms. Organizations should enforce mandatory browser update policies and consider implementing additional security layers such as content security policies and extended validation certificates. Security professionals should monitor for indicators of compromise related to suspicious URL patterns and implement user education programs that emphasize the importance of verifying domain names through multiple methods beyond visual inspection. The vulnerability aligns with CWE-1004 which addresses insecure default conditions in software, and maps to ATT&CK technique T1566.001 related to spearphishing attachments, as attackers can leverage this flaw to create more convincing phishing campaigns. Organizations should also consider implementing browser security extensions and web filtering solutions that can detect and block suspicious internationalized domain names, while ensuring that security teams maintain awareness of emerging IDN spoofing techniques that could potentially bypass these protections.