CVE-2020-9945 in Safari
Summary
by MITRE • 12/09/2020
A spoofing issue existed in the handling of URLs. This issue was addressed with improved input validation. This issue is fixed in macOS Big Sur 11.0.1, Safari 14.0.1. Visiting a malicious website may lead to address bar spoofing.
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Analysis
by VulDB Data Team • 12/14/2020
This vulnerability represents a critical spoofing flaw in web browser URL handling mechanisms that allows malicious actors to manipulate the visual representation of web addresses. The issue manifests as address bar spoofing where users may be deceived into believing they are visiting a legitimate website when in fact they are accessing a fraudulent or malicious page. This type of vulnerability directly undermines user trust and can lead to significant security risks including credential theft, financial fraud, and data exfiltration. The flaw specifically affects how browsers process and display URL information, creating a window for attackers to exploit the trust users place in visual address indicators.
The technical implementation of this vulnerability stems from insufficient input validation mechanisms within the browser's URL processing pipeline. When handling URLs, the affected browsers failed to properly sanitize or validate the input data, allowing specially crafted malicious URLs to bypass normal security checks. This weakness creates a condition where attackers can manipulate the visual display of web addresses without triggering appropriate security warnings or alerts. The vulnerability operates at the application layer and can be classified under CWE-601 as URL Redirection to Untrusted Site, where the browser fails to properly validate the destination of redirected URLs. The flaw particularly affects the user interface components responsible for displaying website addresses, creating a false sense of security for users who rely on address bar information for verification.
The operational impact of this vulnerability extends beyond simple deception to create serious risks for end users and organizations. When users visit malicious websites, they may unknowingly enter sensitive information into forms that appear to be legitimate but are actually controlled by attackers. The vulnerability is particularly dangerous in phishing campaigns where attackers can make their malicious sites appear to be trusted entities such as banks, social media platforms, or corporate portals. This spoofing capability can lead to successful social engineering attacks that bypass traditional security controls, as users trust the visual indicators provided by the browser interface. The issue affects all users of the vulnerable browser versions and can be exploited through various attack vectors including malicious links in emails, compromised websites, or social media platforms.
Mitigation strategies for this vulnerability focus on immediate software updates and enhanced user awareness. The primary solution involves applying the security patches released by Apple as part of macOS Big Sur 11.0.1 and Safari 14.0.1 updates, which implement improved input validation mechanisms. Organizations should ensure all affected systems receive these updates promptly and establish monitoring procedures to detect potential exploitation attempts. Security teams should also implement browser hardening measures including enhanced URL validation policies, network monitoring for suspicious URL patterns, and user education programs that emphasize the importance of verifying website addresses through multiple methods. From an ATT&CK framework perspective, this vulnerability maps to technique T1566 which involves phishing through social engineering, and T1071.001 which covers application layer protocol usage. Organizations should consider implementing additional security controls such as web application firewalls and content filtering solutions to provide defense in depth against exploitation attempts. The vulnerability also highlights the need for continuous security testing of browser components and regular vulnerability assessments to identify similar issues in other web application interfaces.