dbcve.org
Ssh SlaveApplication · Jenkins

CVE-2025-32755

CRITICAL · 9.1 CVSS v3.1 Published 2025-04-10
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
In jenkins/ssh-slave Docker images based on Debian, SSH host keys are generated on image creation for images based on Debian, causing all containers based on images of the same version use the same SSH host keys, allowing attackers able to insert themselves into the network path between the SSH client (typically the Jenkins controller) and SSH build agent to impersonate the latter.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

In jenkins/ssh-slave Docker images based on Debian, SSH host keys are generated during image build time rather than container runtime. This means all containers spawned from images of the same version share identical SSH host keys, enabling a network attacker positioned between the Jenkins controller and SSH build agent to perform man-in-the-middle attacks and impersonate the build agent.

MitigationRegenerate SSH host keys at container runtime by implementing a custom entrypoint script that generates unique host keys on each container start, or migrate to images with runtime key generation.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Ssh SlaveApplication
Affected:all versions

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify if Jenkins SSH agent Docker image is in use
    Inspect running containers: `docker ps` or `kubectl get pods` and look for images named 'jenkins/ssh-slave', 'jenkins/ssh-agent', or similar Jenkins SSH agent images
    Affected if The environment uses a Jenkins SSH agent Docker image derived from the official jenkins/ssh-slave base image without runtime key generation customization
  2. Check SSH host key file timestamps
    Inside the container, inspect the SSH host key timestamps: `ls -la /etc/ssh/ssh_host*_key*` or from the host `docker exec <container> ls -la /etc/ssh/ssh_host*_key*`
    Affected if The host key files have timestamps corresponding to the image build date (months or years ago) rather than recent container startup time, indicating keys were baked into the image
  3. Verify if host keys are identical across container restarts
    Restart the container and compare the SSH host keys: `docker exec <container> cat /etc/ssh/ssh_host_rsa_key` before and after restart, or compare between two freshly created containers
    Affected if The SSH host keys remain identical after container restart or are identical across different container instances, confirming they were generated at build time not runtime
  4. Check for runtime key generation entrypoint
    Inspect the container's entrypoint or startup command: `docker inspect <container> --format '{{.Config.Entrypoint}}'` and look for custom scripts that execute ssh-keygen at startup
    Affected if No custom entrypoint script exists that generates unique SSH host keys on each container startup (i.e., using default image entrypoint)
  5. Examine image build history for key generation
    If accessible, inspect the Docker image history: `docker history <image>` or check the Dockerfile if custom image is built, looking for ssh-keygen commands during build
    Affected if The image history shows ssh-keygen was executed during the image build layer rather than having a startup script for runtime key generation

The environment is affected if running a Jenkins SSH agent Docker image where SSH host keys have old timestamps, remain unchanged across container restarts, or no custom entrypoint generates keys at runtime.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Regenerate SSH host keys at container runtime by implementing a custom entrypoint script that generates unique host keys on each container start, or migrate to images with runtime key generation.

Fix this in Ssh Slave Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,780
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-32755 in production — separate from our analysis above.

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What this is

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What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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