JunosOperating system · Juniper

CVE-2015-7751

MEDIUM · 6.9 CVSS v2.0 Published 2015-10-19
Fix available
A fix is available. Upgrade to after 12.1x44 or later.
See remediation →
74/100
Remediation priority · Elevated
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 Junos OS before 12.1X44-D50, 12.1X46 before 12.1X46-D35, 12.1X47 before 12.1X47-D25, 12.3 before 12.3R9, 12.3X48 before 12.3X48-D15, 13.2 before 13.2R7, 13.2X51 before 13.2X51-D35, 13.3 before 13.3R6, 14.1 before 14.1R5, 14.1X50 before 14.1X50-D105, 14.1X51 before 14.1X51-D70, 14.1X53 before 14.1X53-D25, 14.1X55 before 14.1X55-D20, 14.2 before 14.2R1, 15.1 before 15.1F2 or 15.1R1, and 15.1X49 before 15.1X49-D10 does not require a password for the root user when pam.conf is "corrupted," which allows local users to gain root privileges by modifying the file.

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

Junos OS contains a vulnerability in its PAM (Pluggable Authentication Modules) configuration where the pam.conf file can be modified to bypass root password authentication. When pam.conf is in a specific corrupted state, local users can gain unrestricted root privileges without providing a password.

MitigationUpgrade Junos OS to the fixed versions (12.1X44-D50+, 12.1X46-D35+, 12.3R9+, 13.2R7+, 14.1R5+, 15.1F2+, 15.1X49-D10+). Additionally, verify pam.conf integrity and monitor for unauthorized modifications.

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
JunosOperating system
Affected:<= 12.1x44= 12.1x46= 12.1x47= 12.3= 12.3x48= 13.2= 13.2x51= 13.3= 14.1= 14.1x50= 14.1x51= 14.1x53

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
Local
Complexity
M
Authentication
None
Confidentiality
Complete
Integrity
Complete
Availability
Complete

AV:L/AC:M/Au:N/C:C/I:C/A:C

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. Check Junos OS version
    Run 'show version' command on the Junos device
    Affected if Version matches one of the affected releases: 12.1x44 and earlier, 12.1x46, 12.1x47, 12.3, 12.3x48, 13.2, 13.2x51, 13.3, 14.1, 14.1x50, 14.1x51, or 14.1x53
  2. Verify pam.conf file integrity
    Retrieve /etc/pam.conf and calculate its checksum or compare to a known-good baseline configuration
    Affected if The file has been modified from its expected state or shows signs of corruption
  3. Inspect pam.conf for abnormal entries
    Read /etc/pam.conf and examine the authentication stack configuration for any entries that could cause authentication to fail open or bypass password verification
    Affected if The configuration contains unexpected or malformed auth entries that would skip password checking
  4. Check for unauthorized root access attempts
    Review system logs for successful root logins without password prompt or authentication failures that succeeded
    Affected if Logs show root access was gained without valid password authentication

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 12.1x44
Interim mitigation

Upgrade Junos OS to the fixed versions (12.1X44-D50+, 12.1X46-D35+, 12.3R9+, 13.2R7+, 14.1R5+, 15.1F2+, 15.1X49-D10+). Additionally, verify pam.conf integrity and monitor for unauthorized modifications.

Fix this in Junos Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,490
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,984.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2015-7751 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

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-2015-7751 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