CVE-2022-29245

Description

SSH.NET is a Secure Shell (SSH) library for .NET. In versions 2020.0.0 and 2020.0.1, during an `X25519` key exchange, the client’s private key is generated with `System.Random`. `System.Random` is not a cryptographically secure random number generator, it must therefore not be used for cryptographic purposes. When establishing an SSH connection to a remote host, during the X25519 key exchange, the private key is generated with a weak random number generator whose seed can be brute forced. This allows an attacker who is able to eavesdrop on the communications to decrypt them. Version 2020.0.2 contains a patch for this issue. As a workaround, one may disable support for `curve25519-sha256` and `curve25519-sha256@libssh.org` key exchange algorithms.

Weakness classification

• security-advisories@github.com: CWE-338

Primary references

• security-advisories@github.com — Exploit, Third Party Advisory
• security-advisories@github.com — Patch, Third Party Advisory
• security-advisories@github.com — Release Notes, Third Party Advisory
• security-advisories@github.com — Exploit, Mitigation, Third Party Advisory
• af854a3a-2127-422b-91ae-364da2661108 — Exploit, Third Party Advisory
• af854a3a-2127-422b-91ae-364da2661108 — Patch, Third Party Advisory
• af854a3a-2127-422b-91ae-364da2661108 — Release Notes, Third Party Advisory
• af854a3a-2127-422b-91ae-364da2661108 — Exploit, Mitigation, Third Party Advisory