Denial of service in Go programming language

1) Improper Certificate Validation

EUVDB-ID: #VU55665

Risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-34558

CWE-ID: CWE-295 - Improper Certificate Validation

Exploit availability: Yes

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to improper certificate verification in crypto/tls package in Go when processing X.509 certificates. The application does not properly assert that the type of public key in an X.509 certificate matches the expected type when doing a RSA based key exchange, allowing a malicious TLS server to cause a TLS client to panic.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Go programming language: 1.16 - 1.16.5

External links

http://groups.google.com/g/golang-announce
http://groups.google.com/g/golang-announce/c/n9FxMelZGAQ
http://golang.org/doc/devel/release#go1.16.minor
http://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/3BA7MFVXRBEKRTLSLYDICTYCGEMK2HZ7/
http://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/D7FRFM7WWR2JCT6NORQ7AO6B453OMI3I/
http://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/WXJ2MVMAHOIGRH37ZSFYC4EVWLJFL2EQ/
http://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/JYIUSR4YP52PWG7YE7AA3DZ5OSURNFJB/

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.