CVE-2017-5072 in Chrome
Summary
by MITRE
Inappropriate implementation in Omnibox in Google Chrome prior to 59.0.3071.92 for Android allowed a remote attacker to perform domain spoofing with RTL characters via a crafted URL page.
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Analysis
by VulDB Data Team • 01/04/2023
The vulnerability identified as CVE-2017-5072 represents a critical security flaw in Google Chrome's Omnibox implementation on Android platforms. This issue stems from an inadequate handling of right-to-left text rendering in URL display mechanisms, creating a significant vector for user deception and potential phishing attacks. The vulnerability specifically affects Chrome versions prior to 59.0.3071.92, where the browser's address bar fails to properly sanitize and display URLs containing right-to-left characters, allowing malicious actors to craft deceptive web addresses that appear legitimate to unsuspecting users.
The technical root cause of this vulnerability lies in how Chrome processes and renders Unicode characters within URL strings, particularly when right-to-left scripts such as Arabic or Hebrew are present. When a user encounters a maliciously crafted URL containing RTL characters, the browser's rendering engine incorrectly displays the URL in a manner that obscures the true domain name. This occurs because the Unicode bidirectional algorithm, which governs text direction in mixed-script environments, is not properly enforced during URL display. Attackers can exploit this by placing legitimate domain characters in the left portion of the URL while embedding malicious characters in the right portion, creating a visual representation that appears to show a trusted website while actually directing users to a fraudulent destination.
This vulnerability directly maps to CWE-174, which addresses the weakness of insufficient input validation in bidirectional text processing, and aligns with ATT&CK technique T1566.001 for credential access through spearphishing attachments and T1531 for account access through social engineering. The operational impact of CVE-2017-5072 extends beyond simple visual deception, as it enables sophisticated phishing campaigns that can bypass traditional security measures. Users who rely on visual inspection of URLs for security verification may be misled into trusting malicious websites, potentially leading to credential theft, financial fraud, or malware installation. The vulnerability particularly affects mobile users who may have reduced ability to scrutinize URLs due to screen size limitations and the increased prevalence of mobile-based attacks.
The security implications of this flaw are substantial, as it demonstrates how seemingly minor implementation details in text rendering can create significant attack vectors. The vulnerability allows for domain spoofing attacks where attackers can make malicious URLs appear to originate from legitimate domains such as banks, social media platforms, or government websites. This creates a high-risk environment for users who may not notice the subtle differences in URL display, especially when browsing on mobile devices where screen real estate is limited. The attack requires minimal technical skill to execute, making it particularly dangerous for widespread exploitation. Organizations should note that this vulnerability highlights the importance of comprehensive input validation and proper handling of international character sets in security-critical applications. The remediation strategy involves updating to Chrome version 59.0.3071.92 or later, which implements proper Unicode bidirectional text handling and URL display sanitization. Additionally, users should be educated about the importance of verifying full URLs rather than relying solely on visual appearance, particularly when navigating to sensitive websites. Security teams should also consider implementing additional monitoring for suspicious URL patterns and user behavior that might indicate phishing attempts.