iOSOperating system · Cisco
CVE-2016-1378
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 · uneditedCisco IOS before 15.2(2)E1 on Catalyst switches allows remote attackers to obtain potentially sensitive software-version information via a request to the Network Mobility Services Protocol (NMSP) port, aka Bug ID CSCum62591.
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 confidenceThis vulnerability in Cisco IOS before 15.2(2)E1 on Catalyst switches allows remote attackers to obtain potentially sensitive software version information by sending a request to the Network Mobility Services Protocol (NMSP) port. The information disclosed could aid attackers in reconnaissance and targeting subsequent exploits specific to the identified version.
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
iOSOperating system
= 15.1\(1\)sg= 15.1\(1\)sg1= 15.1\(1\)sg2= 15.1\(1\)sy= 15.1\(1\)sy1= 15.1\(1\)sy2= 15.1\(1\)sy3= 15.1\(1\)sy4= 15.1\(1\)sy5= 15.1\(1\)sy6= 15.1\(2\)sg= 15.1\(2\)sg1CVSS 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
- Low
- Integrity
- None
- Availability
- None
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/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 checksWork through these to decide whether this CVE applies to you.
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Identify the Cisco IOS versionExecute 'show version' on the device CLI and locate the 'IOS' or 'IOS-XE' version string in the outputAffected if The version matches any of: 15.1(1)sg, 15.1(1)sg1, 15.1(1)sg2, 15.1(1)sy, 15.1(1)sy1, 15.1(1)sy2, 15.1(1)sy3, 15.1(1)sy4, 15.1(1)sy5, 15.1(1)sy6, 15.1(2)sg, or 15.1(2)sg1, or is any version prior to 15.2(2)E1 on the listed train
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Confirm the device is a Catalyst switchReview the 'show version' output for model identification such as 'Catalyst 2960', 'Catalyst 3750', or similar Catalyst series designationsAffected if The device is a Cisco Catalyst switch model running the affected IOS versions listed above
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Verify NMSP service statusExecute 'show nmsp status' or 'show running-config | include nmsp' to determine if Network Mobility Services Protocol is enabled on the deviceAffected if NMSP is enabled and operational on the device
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Check NMSP port accessibilityFrom an external host, attempt to TCP connect to port 9991 on the device IP address using tools such as 'telnet <ip> 9991' or 'nc -zv <ip> 9991' to test if the NMSP port is reachableAffected if TCP port 9991 is open and accepts connections from untrusted network segments
The environment is affected if the device runs any Cisco IOS version prior to 15.2(2)E1 from the 15.1 train listed, is a Catalyst switch, and has NMSP service enabled with TCP port 9991 accessible from the network.
Generated from the published advisory. Verify against your own configuration.
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 dataUpgrade to Cisco IOS 15.2(2)E1 or later to resolve this vulnerability. If immediate upgrade is not feasible, restrict network access to NMSP port (TCP 9991) from untrusted sources as a compensating control.
Fix this in iOS
Scoped from the published advisory
- Consultation3.0 h
- Implementation3.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2016-1378 — 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 sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2016-1378 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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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.
- 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
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