ScreenosOperating system · Juniper

CVE-2015-7754

HIGH · 8.1 CVSS v3.0 Published 2016-01-08
Fix available
A fix is available. Upgrade to after 6.3.0 or later.
See remediation →
90/100
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
Juniper ScreenOS before 6.3.0r21, when ssh-pka is configured and enabled, allows remote attackers to cause a denial of service (system crash) or execute arbitrary code via crafted SSH negotiation.

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

This vulnerability affects Juniper ScreenOS VPN/firewall devices prior to version 6.3.0r21. When the SSH public key authentication (ssh-pka) feature is configured and enabled, remote attackers can send crafted SSH negotiation messages to cause either a denial of service (system crash) or execute arbitrary code on the affected device.

MitigationUpgrade Juniper ScreenOS to version 6.3.0r21 or later. If immediate patching is not feasible, consider disabling the ssh-pka feature or restricting SSH access to trusted management networks until the upgrade can be scheduled.

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
ScreenosOperating system
Affected:<= 6.3.0

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
High
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

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 the device and operating system
    Run 'get version' or 'show version' on the device console to confirm it is a Juniper ScreenOS device
    Affected if The device is not running Juniper ScreenOS (not applicable)
  2. Check the ScreenOS version
    Review the version number output from 'get version' or 'show version' and compare it to the affected range of versions prior to 6.3.0r21
    Affected if The installed version is 6.3.0 or any version lower than 6.3.0r21
  3. Verify SSH is enabled
    Run 'get ssh' or 'show ssh' to check if SSH service is configured on the device
    Affected if SSH is not enabled on the device (not affected)
  4. Check if SSH public key authentication (ssh-pka) is configured
    Run 'get ssh pubkey-authentication' or 'show ssh pka' to determine whether the ssh-pka feature is enabled
    Affected if The ssh-pka feature is enabled - this is the condition required for the vulnerability to be exploitable

The device is affected if it runs ScreenOS version 6.3.0 or lower AND has the SSH public key authentication (ssh-pka) feature enabled.

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
Upgrade available Upgrade to a release after 6.3.0
Interim mitigation

Upgrade Juniper ScreenOS to version 6.3.0r21 or later. If immediate patching is not feasible, consider disabling the ssh-pka feature or restricting SSH access to trusted management networks until the upgrade can be scheduled.

Fix this in Screenos Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
18.0 hours of engineering $3,200
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Scan for this in your stack

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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-2015-7754 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data