JunosOperating system · Juniper

CVE-2015-7749

HIGH · 7.8 CVSS v2.0 Published 2015-10-19
Fix available
A fix is available. Upgrade to after 15.1x49 or later.
See remediation →
87/100
Remediation priority · High
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
The PFE daemon in Juniper vSRX virtual firewalls with Junos OS before 15.1X49-D20 allows remote attackers to cause a denial of service via an unspecified connection request to the "host-OS."

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 · moderate confidence

A denial of service vulnerability exists in the Packet Forwarding Engine (PFE) daemon of Juniper vSRX virtual firewalls running Junos OS versions prior to 15.1X49-D20. Remote attackers can exploit an unspecified connection request to the host-OS component to cause the PFE daemon to become unavailable, disrupting packet forwarding capabilities.

MitigationUpgrade Junos OS on vSRX virtual firewalls to version 15.1X49-D20 or later. Restrict management access to trusted networks as a defense-in-depth measure until patching is completed.

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:<= 15.1x49

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
Authentication
None
Confidentiality
None
Integrity
None
Availability
Complete

AV:N/AC:L/Au:N/C:N/I:N/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. Identify if the device is a vSRX virtual firewall
    Check the system model or product name via 'show system hardware' or 'show version' command output. Look for vSRX, vsrx, or virtual firewall indicators in the hardware/model information.
    Affected if The device is a Juniper vSRX virtual firewall (physical vSRX appliances are also affected based on the product type)
  2. Determine the installed Junos OS version
    Execute 'show version' or 'show version detail' on the device CLI. Locate the Junos OS version string (typically displayed as something like 15.1X49-D10 or similar).
    Affected if The Junos version is 15.1X49-D20 or lower, or matches a version string beginning with 15.1 and containing 'X49' with a build number less than 20
  3. Confirm the PFE daemon is active
    Check PFE daemon status via 'show pfe status' or 'show system processes' commands. The vulnerability requires the Packet Forwarding Engine daemon to be running for exploitation.
    Affected if The PFE daemon is operational (this is the default state for a functioning vSRX)
  4. Check for unauthorized or anomalous connection attempts
    Review system logs and security logs for connection requests to the host-OS component. Look for patterns of connection requests that may have triggered daemon unavailability. Use 'show log messages' or 'show system syslog' to search for PFE-related errors.
    Affected if Logs show PFE daemon crashes, unavailability events, or connection request anomalies around the time of potential exploitation

A system is affected if it is a vSRX virtual firewall running any Junos OS version at or below 15.1X49-D20 (versions prior to 15.1X49-D20), with the PFE daemon actively running.

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 15.1x49
Interim mitigation

Upgrade Junos OS on vSRX virtual firewalls to version 15.1X49-D20 or later. Restrict management access to trusted networks as a defense-in-depth measure until patching is completed.

Fix this in Junos Scoped from the published advisory
  • Consultation3.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,770
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,832.

Scan for this in your stack

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dbcve dependency scanner

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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-2015-7749 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