Vulnerability identifier: #VU9527

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-2017-7843

CWE-ID: CWE-284

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 in web worker while in Private Browsing mode due to improper input validation. A remote attacker can trick the victim into visiting a specially crafted website, bypass private-browsing protections and uniquely fingerprint visitors.to write persistent data to IndexedDB, which was not cleared when exiting and would persist across multiple sessions.

Mitigation
Update to version 57.0.1.

Vulnerable software versions

Mozilla Firefox: 52.0.2 - 57.0

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External links
http://www.mozilla.org/en-US/security/advisories/mfsa2017-27/

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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.