#VU69451 Man-in-the-Middle (MitM) attack in crypto - CVE-2017-3204

Vulnerability identifier: #VU69451

Vulnerability risk: Medium

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2017-3204

CWE-ID: CWE-300

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
crypto
Universal components / Libraries / Libraries used by multiple products

Vendor: Go

Description

The vulnerability allows a remote attacker to perform MitM attack.

The vulnerability exists due to Go Crypto library does not verify host keys. A remote attacker can perform MitM attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

crypto: before 0.1.0

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External links
https://bridge.grumpy-troll.org/2017/04/golang-ssh-security/
https://github.com/golang/crypto/commit/e4e2799dd7aab89f583e1d898300d96367750991
https://github.com/golang/go/issues/19767
https://godoc.org/golang.org/x/crypto/ssh

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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.