CVE-2017-5105 in Chrome
Summary
by MITRE
Insufficient Policy Enforcement in Omnibox in Google Chrome prior to 60.0.3112.78 for Mac, Windows, Linux, and Android allowed a remote attacker to perform domain spoofing via IDN homographs in a crafted domain name.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 01/05/2023
The vulnerability identified as CVE-2017-5105 represents a critical security flaw in Google Chrome's handling of Internationalized Domain Names in Applications which falls under the category of insufficient policy enforcement. This weakness specifically affects the omnibox component responsible for displaying and processing URL addresses in the browser interface. The vulnerability stems from Chrome's inadequate validation of internationalized domain names that utilize homograph characters, which are Unicode characters that visually resemble standard latin characters but have different unicode code points. Attackers can exploit this by crafting malicious domain names that appear identical to legitimate websites but contain hidden unicode characters that are indistinguishable to the human eye. This particular flaw impacts all supported platforms including Mac, Windows, Linux, and Android versions of Chrome prior to 60.0.3112.78, making it a widespread concern across the user base.
The technical implementation of this vulnerability involves the browser's failure to properly sanitize and validate domain names when displaying them in the omnibox interface. When users encounter a crafted malicious domain name, Chrome displays the visual representation while internally storing and processing the actual unicode characters that make up the domain. This creates a scenario where legitimate users might be deceived into believing they are visiting a trusted website when they are actually navigating to a malicious site that uses visually identical characters but different unicode code points. The flaw operates at the presentation layer of the browser, specifically targeting the user interface component that displays URL information to users. According to CWE classification, this vulnerability maps to CWE-1004 which describes insufficient policy enforcement, and it aligns with ATT&CK technique T1059.001 related to command and scripting interpreter for executing malicious code through browser-based attacks. The vulnerability essentially allows for a form of visual spoofing that bypasses traditional security mechanisms designed to prevent such deceptive practices.
The operational impact of CVE-2017-5105 is significant as it enables sophisticated phishing attacks that can deceive even technically savvy users. Attackers can register domain names that appear identical to well-known organizations such as banks, social media platforms, or government websites by utilizing homograph characters that visually match the target domain. This creates a highly effective vector for credential theft, malware distribution, and other malicious activities that rely on user trust and deception. The vulnerability is particularly dangerous because users cannot easily distinguish between legitimate and malicious domains through visual inspection alone, making it difficult to detect and prevent attacks. The attack surface extends beyond simple phishing to include more complex social engineering campaigns where attackers can leverage the visual similarity to create convincing fraudulent web pages. This flaw essentially undermines the fundamental security principle of user trust in browser navigation and can lead to widespread compromise of user credentials and sensitive data.
Mitigation strategies for CVE-2017-5105 require immediate patching of affected Chrome versions to 60.0.3112.78 or later, which includes proper implementation of unicode normalization and validation for domain names. Organizations should implement comprehensive browser security policies that include regular updates and monitoring for similar vulnerabilities. Users should be educated about the risks of visual spoofing and trained to verify URLs through multiple methods including checking for secure connection indicators and examining the full domain name rather than relying solely on visual appearance. The fix implemented by Google involved enhancing the domain name validation process to properly handle unicode characters and prevent the display of visually deceptive domain names while maintaining functionality for legitimate internationalized domain names. Security teams should also consider implementing additional monitoring for suspicious domain registrations and network traffic patterns that might indicate attempts to exploit this vulnerability. This vulnerability highlights the importance of proper internationalization handling in security-critical applications and demonstrates the need for comprehensive testing of user interface components that handle potentially malicious input.