CVE-2023-52263 in Brave
Summary
by MITRE • 12/30/2023
Brave Browser before 1.59.40 does not properly restrict the schema for WebUI factory and redirect. This is related to browser/brave_content_browser_client.cc and browser/ui/webui/brave_web_ui_controller_factory.cc.
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Analysis
by VulDB Data Team • 01/22/2024
The vulnerability identified as CVE-2023-52263 represents a critical security flaw in the Brave Browser version 1.59.40 and earlier, which stems from inadequate schema restrictions within the WebUI factory and redirect mechanisms. This issue specifically affects the browser/brave_content_browser_client.cc and browser/ui/webui/brave_web_ui_controller_factory.cc components, which are responsible for handling web-based user interface elements and content routing within the browser environment. The flaw allows for potential unauthorized access to internal browser functionality through maliciously crafted URLs or web requests that exploit the overly permissive schema validation.
The technical nature of this vulnerability can be categorized under CWE-20, which deals with improper input validation, and more specifically relates to CWE-732, inadequate restriction of operations within a recognized security boundary. The vulnerability manifests when the browser fails to properly validate the schema of URLs passed to the WebUI factory and redirect mechanisms, potentially allowing attackers to manipulate the browser's internal navigation and content handling processes. This occurs because the WebUI controller factory does not sufficiently restrict which schemas can be used to access internal browser components, creating an attack surface where malicious actors could potentially access sensitive browser functionality or redirect users to unintended destinations.
Operationally, this vulnerability poses significant risks to user security and privacy within the Brave browser environment. Attackers could exploit this flaw to perform malicious redirects that lead users to phishing sites or other harmful content while appearing to originate from legitimate browser components. The impact extends beyond simple redirection attacks as the vulnerability could potentially allow for privilege escalation or information disclosure if the WebUI components handle sensitive user data or system functions. Users who browse the web using vulnerable versions of Brave may unknowingly expose themselves to attacks that leverage the browser's own internal mechanisms against them, particularly in scenarios involving drive-by downloads or social engineering attacks.
The mitigation strategy for CVE-2023-52263 requires immediate upgrading to Brave Browser version 1.59.40 or later, which contains the necessary patches to properly restrict schema validation for WebUI factory and redirect operations. Organizations should also implement network-level monitoring to detect unusual WebUI traffic patterns that might indicate exploitation attempts. Additionally, browser security policies should be reviewed to ensure that no custom configurations are bypassing the schema validation mechanisms. This vulnerability aligns with ATT&CK technique T1059.001, which covers command and scripting interpreter, as exploitation may involve crafting malicious URLs or scripts that leverage the browser's internal WebUI components. System administrators should also consider implementing browser hardening measures such as disabling unnecessary WebUI features and enforcing strict content security policies to reduce the attack surface. The fix implemented in version 1.59.40 addresses the root cause by strengthening schema validation logic in the WebUI controller factory, ensuring that only properly validated and authorized schemas can access internal browser components, thereby preventing unauthorized access to sensitive functionality.