iOSOperating system · Cisco
CVE-2018-0169
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 · uneditedMultiple vulnerabilities in the CLI parser of Cisco IOS XE Software could allow an authenticated, local attacker to gain access to the underlying Linux shell of an affected device and execute arbitrary commands with root privileges on the device. The vulnerabilities are due to the affected software improperly sanitizing command arguments to prevent access to internal data structures on a device. An attacker who has user EXEC mode (privilege level 1) access to an affected device could exploit these vulnerabilities on the device by executing CLI commands that contain crafted arguments. A successful exploit could allow the attacker to gain access to the underlying Linux shell of the affected device and execute arbitrary commands with root privileges on the device. Cisco Bug IDs: CSCtw85441, CSCus42252, CSCuv95370.
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 CVE encompasses multiple vulnerabilities in the CLI parser of Cisco IOS XE Software. An authenticated attacker with user EXEC mode (privilege level 1) can exploit these vulnerabilities by executing CLI commands containing crafted arguments. The root cause is improper sanitization of command arguments that should prevent access to internal data structures, allowing the attacker to escape to the underlying Linux shell and execute arbitrary commands with root privileges.
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
= 15.0\(5.59\)emdCVSS 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
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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 checksWork through these to decide whether this CVE applies to you.
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Identify the device product typeRun 'show version' or 'show inventory' to confirm the device runs Cisco IOS XE Software rather than classic Cisco IOSAffected if The device runs Cisco IOS XE Software
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Determine the installed IOS XE versionExecute 'show version' and locate the version string (for example, 16.x.x or 15.x.x). Compare this version against the affected version 15.0(5.59)emd as listed in the advisory.Affected if The installed version matches exactly 15.0(5.59)emd
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Verify authentication methods enabledCheck the running configuration for lines like 'line vty', 'login', or 'transport input ssh' to see if remote authentication is enabled.Affected if Remote access via VTY, SSH, or Telnet is enabled and allows privilege level 1 user access
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Check privilege level configurationReview the configuration for any 'privilege level' settings under line vty or local user accounts. Execute 'show privilege' to see current user privilege level.Affected if Privilege level 1 (user EXEC) users can access the device remotely or locally
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Confirm CLI parser accessibilityAttempt to access the device via console or remote access and verify the CLI is accessible with any valid user account.Affected if An authenticated user with privilege level 1 can access the CLI
The device is affected if it runs Cisco IOS XE version 15.0(5.59)emd AND has an authenticated user with privilege level 1 able to access the CLI (locally or remotely).
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 dataApply the vendor-supplied patches for Cisco IOS XE Software as identified in the Cisco Security Advisory. If patching is not immediately possible, restrict physical and console access to trusted personnel only, as this is a local authenticated attack requiring privilege level 1 access.
Fix this in iOS
Scoped from the published advisory
- Consultation4.0 h
- Implementation8.0 h
- Testing4.0 h
- Review / QA2.0 h
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 locallyCheck whether your project pulls in CVE-2018-0169 — 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-2018-0169 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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