#VU8630 WebCrypto allows AES-GCM with 0-length IV in Mozilla Firefox - CVE-2017-7822

Vulnerability identifier: #VU8630

Vulnerability risk: Low

CVSSv4.0: 1.2 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2017-7822

CWE-ID: CWE-310

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 gain access to potentially sensitive information.

The AES-GCM implementation in WebCrypto API accepts 0-length IV when it should require a length of 1 according to the NIST Special Publication 800-38D specification. This might allow for the authentication key to be determined in some instances.

Mitigation
Update to version 56.0.

Vulnerable software versions

Mozilla Firefox: 48.0 - 55.0.3

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External links
https://www.mozilla.org/en-US/security/advisories/mfsa2017-21/

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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.