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CVE-2020-28942

MEDIUMCVSS 4.3/10EPSS 0.36%

Last modified

CVE-2020-28942 is a medium-severity vulnerability rated 4.3/10 on the CVSS scale. 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. EPSS estimates a 0.36% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1
4.3/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

EPSS Probability
0.36%

28.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
PrimekeyEjbca< 7.4.3

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2020-28942?
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.
How severe is CVE-2020-28942?
CVE-2020-28942 has a CVSS score of 4.3/10 (MEDIUM severity). The EPSS model estimates a 0.36% probability of exploitation in the next 30 days.
How do I fix CVE-2020-28942?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-28942?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST