Step-CA: Improper Authentication
CVE-2025-44005 is a critical-severity improper authentication vulnerability in Step-CA from Smallstep, with a CVSS 3.1 base score of 10.0 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Step-CA versions: 0.28.4; v0.28.3. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 9.09% chance of exploitation within 30 days, which is in the top 4.62% of all scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of Step-CA you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N. Scored by CNA (cisco.com).
Official description
An attacker can bypass authorization checks and force a Step CA ACME or SCEP provisioner to create certificates without completing certain protocol authorization checks.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Authentication
When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
How developers prevent this class of flaw
- Use an authentication framework or library such as the OWASP ESAPI Authentication feature.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Other references
Other vulnerabilities in Step-CA
- 10.0 Critical severity
Recent Improper Authentication vulnerabilities
- 9.8 Critical severity
- 7.2 High severity
- 8.1 High severity
- 8.2 High severity
- 7.4 High severity
- 8.1 High severity
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