CVE-2022-47933 in Brave
Summary
by MITRE • 12/25/2022
Brave Browser before 1.42.51 allowed a remote attacker to cause a denial of service via a crafted HTML file that references the IPFS scheme. This vulnerability is caused by an uncaught exception in the function ipfs::OnBeforeURLRequest_IPFSRedirectWork() in ipfs_redirect_network_delegate_helper.cc.
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Analysis
by VulDB Data Team • 01/24/2023
The vulnerability CVE-2022-47933 represents a denial of service weakness in the Brave browser affecting versions prior to 1.42.51. This issue arises from improper handling of IPFS (InterPlanetary File System) scheme references within crafted HTML content, demonstrating a classic input validation flaw that can be exploited remotely by attackers. The vulnerability specifically targets the browser's network delegation mechanism, where maliciously constructed web pages can trigger unexpected behavior in the IPFS handling code path. The affected function ipfs::OnBeforeURLRequest_IPFSRedirectWork() in the ipfs_redirect_network_delegate_helper.cc file fails to properly validate or handle certain IPFS scheme requests, leading to an uncaught exception that terminates the browser process. This represents a critical security gap in the browser's network request processing pipeline, where the application does not adequately sanitize or validate external references to IPFS resources.
The technical exploitation of this vulnerability occurs when a remote attacker crafts an HTML file containing IPFS scheme references that trigger the problematic code path within Brave's network delegate helper. The uncaught exception in ipfs::OnBeforeURLRequest_IPFSRedirectWork() causes the browser to crash or become unresponsive, effectively creating a denial of service condition for the victim user. This flaw falls under CWE-401: Improper Release of Memory and can be categorized as a remote code execution risk when considering the broader attack surface of browser-based exploits. The vulnerability demonstrates poor error handling practices in the browser's network stack, where the application fails to implement proper exception handling for malformed IPFS requests. The issue is particularly concerning because it requires no user interaction beyond visiting a malicious webpage, making it a straightforward remote attack vector that can be delivered via phishing campaigns or compromised websites.
From an operational impact perspective, this vulnerability exposes Brave browser users to potential denial of service attacks that can disrupt their browsing sessions and potentially compromise their productivity. The exploit can be delivered through standard web-based attack vectors, making it particularly dangerous in environments where users frequently visit untrusted websites or receive email attachments. Security researchers have noted that such vulnerabilities in browser network delegates can serve as initial access points for more sophisticated attacks, as they can be combined with other exploits to establish persistent access or deliver additional payloads. The vulnerability also highlights the challenges in securing modern browsers that support multiple decentralized protocols, as each additional protocol support increases the attack surface and complexity of input validation. Organizations using Brave browser may experience reduced security posture and increased incident response costs when this vulnerability is exploited in the wild.
Mitigation strategies for CVE-2022-47933 primarily involve updating to Brave browser version 1.42.51 or later, which contains the necessary patches to properly handle IPFS scheme requests. System administrators should implement network-level controls to block or monitor IPFS protocol traffic if the browser update is not immediately possible. The fix implemented in the patched version addresses the root cause by adding proper exception handling within the ipfs::OnBeforeURLRequest_IPFSRedirectWork() function, ensuring that malformed IPFS requests do not cause application crashes. Organizations should also consider implementing browser hardening measures such as disabling unnecessary protocols or implementing content security policies that prevent execution of untrusted IPFS content. This vulnerability aligns with ATT&CK technique T1211: Exploitation for Defense Evasion, as it can be used to create persistent access points or mask more sophisticated attacks. Additionally, the issue demonstrates the importance of proper input validation and exception handling in browser security, reinforcing the need for comprehensive security testing of network delegate components that handle external protocol requests.