Russh is a Rust SSH client and server library. Prior to 0.62.6, the USERAUTH_REQUEST path reached from server::run_stream in russh/src/server/encrypted.rs increments self.common.auth_attempts but never compares it with server::Config.max_auth_attempts. An unauthenticated remote client can continue submitting authentication requests on one connection beyond the configured cap, bypassing the deployments attempt-limiting policy and increasing online guessing opportunity and backend authentication workload. This issue is fixed in version 0.62.6.
Weakness
The product does not implement sufficient measures to prevent multiple failed authentication attempts within a short time frame.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Red Hat Hardened Images | RedHat | openshell-main-0.1.2-0.2.hum1 | * |
Potential Mitigations
Common protection mechanisms include:
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid [REF-1482].
Consider using libraries with authentication capabilities such as OpenSSL or the ESAPI Authenticator. [REF-45]
Related Attack Patterns
- https://cwe.mitre.org/data/definitions/16.html
- https://cwe.mitre.org/data/definitions/49.html
- https://cwe.mitre.org/data/definitions/560.html
- https://cwe.mitre.org/data/definitions/565.html
- https://cwe.mitre.org/data/definitions/600.html
- https://cwe.mitre.org/data/definitions/652.html
- https://cwe.mitre.org/data/definitions/653.html