Vulnerability identifier: #VU7075

Vulnerability risk: Low

CVSSv3.1: 4.6 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2017-7764

CWE-ID: CWE-200

Exploitation vector: Network

Exploit availability: No

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

Vendor: Mozilla

Description
The vulnerability allows a remote attacker to perform spoofing attack.

The weakness exists due to mix of characters from the "Canadian Syllabics" unicode block  with characters from other unicode blocks in the addressbar instead of being rendered as their raw "punycode" form. A remote attacker can use characters confusion to perform domain name spoofing attacks and read arbitrary files.

Successful exploitation of the vulnerability results in information disclosure.

Mitigation
Update to version 52.2.

Vulnerable software versions

Firefox ESR: 52.0.1, 45.0 - 45.8, 38.0 - 38.8.0

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External links
http://www.mozilla.org/en-US/security/advisories/mfsa2017-16/

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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.