CVE-2017-7325 in Yandex
Summary
by MITRE
Yandex Browser before 16.9.0 allows remote attackers to spoof the address bar via window.open.
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Analysis
by VulDB Data Team • 12/25/2019
The vulnerability identified as CVE-2017-7325 affects Yandex Browser versions prior to 16.9.0 and represents a significant security flaw in the browser's address bar validation mechanism. This issue enables remote attackers to manipulate the browser's address bar display through the window.open JavaScript function, creating a deceptive user interface that can mislead users about the actual destination of web navigation. The flaw stems from insufficient input validation and sanitization within the browser's rendering engine, specifically in how it handles cross-origin navigation requests initiated through the window.open API. According to CWE-79, this vulnerability falls under the category of Cross-Site Scripting (XSS) due to the browser's failure to properly validate and sanitize the URL parameters passed through the window.open function, which allows attackers to inject malicious content that gets rendered in the address bar context.
The operational impact of this vulnerability extends beyond simple visual deception to potentially enable sophisticated phishing attacks and credential theft operations. Attackers can exploit this flaw to display fake URLs that appear legitimate in the address bar while actually redirecting users to malicious sites, effectively bypassing user security awareness and browser security mechanisms. This type of attack vector aligns with techniques described in the MITRE ATT&CK framework under the T1071.001 tactic for Application Layer Protocol: Web Protocols, where adversaries manipulate web browser interfaces to deceive users. The vulnerability particularly affects users who rely on address bar verification as a security control, as the spoofed URL can appear authentic while the actual navigation target remains hidden from view.
Security researchers have documented that this vulnerability demonstrates a critical flaw in browser sandboxing and privilege separation mechanisms, as the window.open function should not be able to directly influence the address bar display without proper validation. The affected versions of Yandex Browser fail to implement adequate security checks that would normally prevent such cross-origin manipulation of UI elements. This flaw represents a breakdown in the browser's security model where JavaScript execution context can directly manipulate the user interface in ways that bypass standard security boundaries. The vulnerability is particularly concerning because it can be exploited through various attack vectors including malicious websites, compromised advertisements, or phishing emails that contain crafted JavaScript code designed to exploit the window.open functionality.
Mitigation strategies for this vulnerability involve immediate browser updates to version 16.9.0 or later, where the developers have implemented proper input validation and address bar sanitization. Organizations should also consider implementing additional security measures such as web application firewalls that can detect and block suspicious window.open calls, and user education programs that emphasize the importance of verifying URLs through alternative means beyond address bar inspection. Network administrators should monitor for exploitation attempts through security information and event management systems that can detect anomalous JavaScript behavior patterns. The fix implemented by Yandex developers likely includes enhanced validation of URL parameters passed to window.open functions, proper sanitization of address bar content, and stricter enforcement of same-origin policies that prevent unauthorized manipulation of UI elements across different security contexts. This vulnerability underscores the critical importance of maintaining up-to-date browser software and implementing defense-in-depth strategies that protect against both known and emerging threats in web browser environments.