Mozilla Firefox up to 139 on Android URL querystring redirect

Summaryinfo

A vulnerability identified as problematic has been detected in Mozilla Firefox up to 139 on Android. Affected is an unknown function of the component URL Handler. The manipulation of the argument querystring leads to redirect. This vulnerability is listed as CVE-2025-6428. The attack may be initiated remotely. There is no available exploit. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Mozilla Firefox up to 139 on Android and classified as problematic. This issue affects some unknown functionality of the component URL Handler. The manipulation of the argument querystring with an unknown input leads to a redirect vulnerability. Using CWE to declare the problem leads to CWE-601. A web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a Redirect. This simplifies phishing attacks. Impacted is integrity. The summary by CVE is:

When a URL was provided in a link querystring parameter, Firefox for Android would follow that URL instead of the correct URL, potentially leading to phishing attacks. *This bug only affects Firefox for Android. Other versions of Firefox are unaffected.* This vulnerability affects Firefox < 140.

It is possible to read the advisory at bugzilla.mozilla.org. The identification of this vulnerability is CVE-2025-6428 since 06/20/2025. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. It demands that the victim is doing some kind of user interaction. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 08/17/2025). The attack technique deployed by this issue is T1204.001 according to MITRE ATT&CK.

The vulnerability scanner Nessus provides a plugin with the ID 242306 (SUSE SLES12 Security Update : MozillaFirefox, MozillaFirefox-branding-SLE (SUSE-SU-2025:02339-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 140 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (242306) and CERT Bund (WID-SEC-2025-1850). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

• Xerox FreeFlow Print Server

Productinfo

Type

• Web Browser

Vendor

• Mozilla

Name

• Firefox

Version

• 139

License

• open-source

Website

• Vendor: https://www.mozilla.org/
• Product: https://www.mozilla.org/en-US/firefox/

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Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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