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RUSTSEC-2023-0027

Published Mar 24, 2023·Last modified Nov 8, 2023
Affected Components(0)

No affected components available

Description

The NATS official Rust clients are vulnerable to MitM when using TLS.

The common name of the server's TLS certificate is validated against the hostname provided by the server's plaintext INFO message during the initial connection setup phase. A MitM proxy can tamper with the host field's value by substituting it with the common name of a valid certificate it controls, fooling the client into accepting it.

Reproduction steps

  1. The NATS Rust client tries to establish a new connection
  2. The connection is intercepted by a MitM proxy
  3. The proxy makes a separate connection to the NATS server
  4. The NATS server replies with an INFO message
  5. The proxy reads the INFO, alters the host JSON field and passes the tampered INFO back to the client
  6. The proxy upgrades the client connection to TLS, presenting a certificate issued by a certificate authority present in the client's keychain. In the previous step the host was set to the common name of said certificate
  7. rustls accepts the certificate, having verified that the common name matches the attacker-controlled value it was given
  8. The client has been fooled by the MitM proxy into accepting the attacker-controlled certificate
Risk Scores
Base Score
0.0

Measures severity based on intrinsic characteristics of the vulnerability, independent of environment.

Threat Intelligence
0.0

No exploitation activity has been observed at this time. Continue routine monitoring.

EPSS
N/A

Probability that this vulnerability will be exploited in the wild within the next 30 days.

Exploit
Not available

We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.

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