#VU69447 Reachable Assertion in crypto - CVE-2020-9283

Vulnerability identifier: #VU69447

Vulnerability risk: Medium

CVSSv4.0: 5.5 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/U:Green]

CVE-ID: CVE-2020-9283

CWE-ID: CWE-617

Exploitation vector: Network

Exploit availability: Yes

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

Vendor: Go

Description

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

The vulnerability exists due to a reachable assertion during signature verification process. A remote attacker can supply a specially crafted certificate to the application (server or client) and perform a denial of service (DoS) attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

crypto: before 0.0.0-20200220183623-bac4c82f6975

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External links
https://groups.google.com/forum/#!topic/golang-announce/3L45YRc91SY
https://packetstormsecurity.com/files/156480/Go-SSH-0.0.2-Denial-Of-Service.html
https://lists.debian.org/debian-lts-announce/2020/10/msg00014.html
https://lists.debian.org/debian-lts-announce/2020/11/msg00027.html
https://lists.debian.org/debian-lts-announce/2020/11/msg00031.html
https://packetstormsecurity.com/files/156480/Go-SSH-0.0.2-Denial-Of-Service.html

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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. However, proof of concept for this vulnerability is available.