dbcve.org
JunosOperating system · Juniper

CVE-2015-5358

HIGH · 7.1 CVSS v2.0 Published 2015-07-14
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
80/100
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
Juniper Junos OS 12.1X44 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, 13.2X52 before 13.2X52-D25, 13.3 before 13.3R6, 14.1R3 before 14.1R3-S2, 14.1 before 14.1R4, 14.1X53 before 14.1X53-D12, 14.1X53 before 14.1X53-D16, 14.1X55 before 14.1X55-D25, 14.2 before 14.2R2, and 15.1 before 15.1R1 allows remote attackers to cause a denial of service (mbuf and connection consumption and restart) via a large number of requests that trigger a TCP connection to move to the LAST_ACK state when there is more data to send.

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

A denial of service vulnerability in Juniper Junos OS allows remote attackers to exhaust mbuf and TCP connection resources by sending a large number of requests that cause TCP connections to become stuck in the LAST_ACK state when additional data remains to be sent, leading to system restart.

MitigationUpgrade Junos OS to the specified fixed versions (12.1X44-D50 and later, 12.1X46-D35 and later, etc.) or apply available patches. Consider implementing rate limiting or connection tracking at network perimeter devices as a compensating control.

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= 12.3x48= 13.2= 13.2x51= 13.2x52= 13.3= 14.1= 14.1x53= 14.1x55= 14.2

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
M
Authentication
None
Confidentiality
None
Integrity
None
Availability
Complete

AV:N/AC:M/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 installed Junos OS version
    Run the command 'show version' or 'show version detail' on the Junos device to display the installed software version
    Affected if The version displayed matches any of the following: 12.1x44, 12.1x46, 12.1x47, 12.3x48, 13.2, 13.2x51, 13.2x52, 13.3, 14.1, 14.1x53, 14.1x55, or 14.2
  2. Inspect TCP connection states
    Run 'show system connections | match LAST_ACK' to view TCP connections stuck in LAST_ACK state, or use 'show tcp connections' to enumerate all TCP connection states
    Affected if A large number of connections remain stuck in LAST_ACK state for extended periods, indicating potential exploitation
  3. Check mbuf resource usage
    Run 'show system mbuf' to display mbuf pool utilization, or use 'show system buffers' to view buffer allocation status
    Affected if Mbuf exhaustion is reported or buffer pools show near-full utilization with little available memory
  4. Review system uptime and restart history
    Run 'show system uptime' to check system uptime and look for recent unexpected reboots, or check 'show system core-dumps' for crash files
    Affected if System uptime is较短 or there are records of unexpected system restarts correlating with high LAST_ACK connection states

If the device runs any of the listed Junos versions AND exhibits abnormal TCP LAST_ACK connection buildup with mbuf exhaustion, the environment is likely affected by this CVE.

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

Upgrade Junos OS to the specified fixed versions (12.1X44-D50 and later, 12.1X46-D35 and later, etc.) or apply available patches. Consider implementing rate limiting or connection tracking at network perimeter devices as a compensating control.

Fix this in Junos 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
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,120.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2015-5358 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2015-5358 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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