[golang.org/x/crypto/ssh] x/crypto/ssh vulnerable to panic via SSH server

The x/crypto/ssh package before 0.0.0-20211202192323-5770296d904e of golang.org/x/crypto allows an attacker to panic an SSH server.

References

• https://nvd.nist.gov/vuln/detail/CVE-2021-43565
• https://groups.google.com/forum/#!forum/golang-announce
• https://groups.google.com/g/golang-announce/c/2AR1sKiM-Qs
• https://github.com/advisories/GHSA-gwc9-m7rh-j2ww