CVE-2020-12412 in Firefox
Summary
by MITRE
By navigating a tab using the history API, an attacker could cause the address bar to display the incorrect domain (with the https:// scheme, a blocked port number such as '1', and without a lock icon) while controlling the page contents. This vulnerability affects Firefox < 70.
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Analysis
by VulDB Data Team • 07/10/2020
This vulnerability represents a sophisticated browser security flaw that exploits the interaction between the history API and address bar rendering mechanisms in Firefox versions prior to 70. The issue stems from how the browser handles tab navigation through the history API, creating a scenario where malicious actors can manipulate the visual representation of the current page while maintaining full control over its contents. The vulnerability specifically targets the user interface elements that display domain information in the address bar, allowing attackers to present misleading domain information to users.
The technical implementation of this flaw involves the history API's ability to manipulate browser navigation without triggering full page reloads, combined with Firefox's address bar update mechanisms. When an attacker navigates tabs using history API methods, the browser's rendering system fails to properly validate or update the displayed domain information, leading to a mismatch between the actual page content and the visual representation in the address bar. This creates a deceptive environment where users see a fake domain with the https:// scheme but with a blocked port number such as '1', lacking the security indicators that would normally appear with legitimate secure connections.
The operational impact of this vulnerability extends beyond simple visual deception, as it creates conditions conducive to phishing attacks and user confusion. Users who rely on address bar information to verify website authenticity may be misled into believing they are visiting legitimate sites when they are actually viewing malicious content. The absence of the security lock icon further compounds the risk, as users typically associate this visual element with secure connections. The blocked port number aspect particularly exploits user expectations about standard web server ports, making the deception more convincing to those familiar with normal internet protocols.
This vulnerability aligns with CWE-601 URL Redirection to Untrusted Site ('Open Redirect') and relates to ATT&CK technique T1059.001 Command and Scripting Interpreter: PowerShell, though it primarily functions through browser UI manipulation rather than direct command execution. The flaw demonstrates the importance of maintaining consistency between browser state management and user interface updates, particularly in security-critical areas like address bar display. Organizations should consider this vulnerability as part of broader browser security assessments, recognizing that UI deception attacks can be as dangerous as direct code execution exploits.
Mitigation strategies for this vulnerability primarily involve updating Firefox to version 70 or later, where the underlying implementation has been corrected. System administrators should ensure all browser installations are current with security patches, particularly in enterprise environments where multiple browser versions may be in use. Additional protective measures include implementing browser security policies that restrict history API usage where possible, and user education about verifying website authenticity through multiple means beyond address bar information. The vulnerability also highlights the need for comprehensive testing of browser UI components to ensure that security indicators remain accurate under all navigation scenarios, particularly those involving programmatic navigation methods.