#VU64805 Input validation error in crypto - CVE-2021-43565
Published: June 29, 2022
Vulnerability identifier: #VU64805
Vulnerability risk: Medium
CVSSv4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2021-43565
CWE-ID: CWE-20
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerable software:
crypto
crypto
Software vendor:
Google
Description
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to insufficient validation of user-supplied input when parsing a Signer to ServerConfig.AddHostKey in cases where the Signer passed to AddHostKey does not implement AlgorithmSigner or the Signer passed to AddHostKey returns a key of type “ssh-rsa” from its PublicKey method. A remote attacker can pass specially crafted input to the application and perform a denial of service (DoS) attack.
Remediation
Install updates from vendor's website.