Skip to main content

Improper Restriction of Excessive Authentication Attempts


Severity High
Score 9.8/10


JumpServer is an open source bastion host. When users enable MFA and use a public key for authentication, the Koko SSH server does not verify the corresponding SSH private key. An attacker could exploit a vulnerability by utilizing a disclosed public key to attempt brute-force authentication against the SSH service. Users are advised to upgrade. There are no known workarounds for this issue. This issue affects all versions of the package

  • LOW
  • HIGH
  • NONE
  • NONE
  • HIGH
  • HIGH

CWE-307 - Improper Restriction of Excessive Authentication Attempts

The software does not implement sufficient measures to prevent multiple failed authentication attempts within in a short time frame, making it more susceptible to brute force attacks.


Advisory Timeline

  • Published