dbcve.org
Actively exploited in the wild. This CVE is on the CISA Known Exploited Vulnerabilities list — treat remediation as urgent. Federal remediation due by 17 Mar 2022.
iOSOperating system · Cisco

CVE-2018-0180

MEDIUM · 5.9 CVSS v3.1 Published 2018-03-28
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
In the wild 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
Multiple vulnerabilities in the Login Enhancements (Login Block) feature of Cisco IOS Software could allow an unauthenticated, remote attacker to trigger a reload of an affected system, resulting in a denial of service (DoS) condition. These vulnerabilities affect Cisco devices that are running Cisco IOS Software Release 15.4(2)T, 15.4(3)M, or 15.4(2)CG and later. Cisco Bug IDs: CSCuy32360, CSCuz60599.

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

Multiple vulnerabilities in the Login Enhancements (Login Block) feature of Cisco IOS Software allow an unauthenticated, remote attacker to trigger a device reload, causing denial of service. The vulnerabilities affect specific IOS releases (15.4(2)T, 15.4(3)M, 15.4(2)CG and later) and are triggered before authentication completes.

MitigationUpgrade Cisco IOS Software to a patched release beyond the affected versions. If immediate patching is not possible, implement network-level access controls to limit exposure to unauthenticated attackers.

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
Affected:= 15.3\(00.00.19\)sy= 15.4\(01\)ia001.100= 15.6\(01.22\)t= 15.4\(03\)m4.1= 15.4\(2\)cg= 15.4\(2\)t= 15.4\(3\)m

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
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/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 Cisco IOS version
    Execute 'show version' on the device and locate the version string in the output (typically the 'Cisco IOS Software' line)
    Affected if The version falls within 15.4(2)T, 15.4(3)M, 15.4(2)CG or later releases, or matches any of these specific versions: 15.3(00.00.19)sy, 15.4(01)ia001.100, 15.6(01.22)t, 15.4(03)m4.1, 15.4(2)cg, 15.4(2)t, 15.4(3)m
  2. Verify if Login Enhancements (Login Block) is configured
    Execute 'show running-config | include login' or 'show running-config | include block' to check for login block configuration lines such as 'login block-for' or 'login quiet-mode access-class'
    Affected if Login Block feature is enabled in the device configuration (login block-for X command is present)
  3. Confirm the device is accessible via network protocols
    Verify the device has active network interfaces (VTY, console with network access) by checking 'show ip interface brief' or 'show interfaces'
    Affected if The device accepts remote network connections before full authentication completes, exposing the vulnerable pre-authentication code path

You are affected if the device runs Cisco IOS version 15.4(2)T, 15.4(3)M, 15.4(2)CG or later and has the Login Enhancements (Login Block) feature configured and active.

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.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade Cisco IOS Software to a patched release beyond the affected versions. If immediate patching is not possible, implement network-level access controls to limit exposure to unauthenticated attackers.

Recommended fix Moderate confidence

Cisco IOS 15.5(3)T or later stable release (15.5.x, 15.6.x, 15.7.x or 16.x train depending on hardware compatibility)

  1. 1. Identify the current Cisco IOS version by running 'show version' on the device
  2. 2. Access Cisco's software download page or use the Cisco IOS Upgrade Planner to obtain the fixed release
  3. 3. Download the appropriate fixed IOS image for your specific hardware platform
  4. 4. Verify the image integrity using the MD5/SHA512 hash provided by Cisco
  5. 5. Upload the new IOS image to the device's flash memory
  6. 6. Configure boot system command to point to the new image: 'boot system flash:<new_image_name>'
  7. 7. Save the configuration: 'write memory'
  8. 8. Reload the device to apply the new IOS: 'reload'
Caveat Review release notes for any feature changes or command syntax modifications between your current version and the target upgrade version before deploying

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in iOS Exploited in the wild — priority engagement
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,980
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,168.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2018-0180 — 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-2018-0180 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