Vulnerability identifier: #VU15496

Vulnerability risk: Low

CVSSv3.1: 5.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L/E:U/RL:O/RC:C]

CVE-ID: CVE-2018-12397

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Mozilla Firefox
Client/Desktop applications / Web browsers

Vendor: Mozilla

Description
The vulnerability allows a remote attacker to bypass security restrictions on the target system.

The weakness exists due to WebExtension can request access to local files without the warning prompt stating that the extension will "Access your data for all websites" being displayed to the user. A remote attacker can trick the victim into visiting a specially crafted website, run content scripts in local pages without permission warnings when a local file is opened.

Mitigation
Update to version 63.0.

Vulnerable software versions

Mozilla Firefox: 62.0 - 62.0.3

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External links
http://www.mozilla.org/en-US/security/advisories/mfsa2018-26/

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.