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Improper Certificate Validation

CVE-2020-28942

Severity Medium
Score 4/10

Summary

An issue exists in PrimeKey EJBCA before 7.4.3 when enrolling with EST while proxied through an RA over the Peers protocol. As a part of EJBCA's domain security model, the peer connector allows the restriction of client certificates (for the RA, not the end user) to a limited set of allowed CAs, thus restricting the accessibility of that RA to the rights it has within a specific role. While this works for other protocols such as CMP, it was found that the EJBCA enrollment over an EST implementation bypasses this check, allowing enrollment with a valid client certificate through any functioning and authenticated RA connected to the CA. NOTE: an attacker must already have a trusted client certificate and authorization to enroll against the targeted CA.

  • LOW
  • NETWORK
  • SINGLE
  • PARTIAL
  • NONE
  • NONE

CWE-295 - Improper Certificate Validation

The authenticity component of a web system stems from the ability to validate “Digital certificates”, which (i) establish trust between two or more entities sharing data over a network; (ii) ensure data at rest and transit is secure from unauthorized access; and (iii) check the identity of the actors that interact with the system. An application with absent or ineffective certificate validation mechanisms allows malicious users, impersonating trusted hosts, to manipulate the communication path between the client and the host, resulting in unauthorized access to data and to the application’s internal environment, and potentially enabling man-in-the-middle attacks.

References

Advisory Timeline

  • Published