Ios XeOperating system · Cisco
CVE-2018-15371
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 · uneditedA vulnerability in the shell access request mechanism of Cisco IOS XE Software could allow an authenticated, local attacker to bypass authentication and gain unrestricted access to the root shell of an affected device. The vulnerability exists because the affected software has insufficient authentication mechanisms for certain commands. An attacker could exploit this vulnerability by requesting access to the root shell of an affected device, after the shell access feature has been enabled. A successful exploit could allow the attacker to bypass authentication and gain unrestricted access to the root shell of the affected device.
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 is a local authentication bypass vulnerability in Cisco IOS XE Software where an authenticated attacker can request root shell access after the shell access feature is enabled, bypassing the authentication mechanism and gaining unrestricted root shell access.
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
Ios XeOperating system
= 16.3\(1\)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
- Local
- Complexity
- Low
- Privileges
- High
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.0/AV:L/AC:L/PR:H/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 Cisco IOS XE versionRun the 'show version' command or check the system banner to confirm the installed IOS XE software versionAffected if The installed version matches 16.3(1)
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Determine if shell access feature is enabledCheck the configuration using 'show running-config | include shell' or review privilege exec configuration. Look for commands like 'privilege exec level' or shell-related configuration in the configuration fileAffected if Shell access or privilege exec shell feature is enabled on the device
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Verify existing user sessions and access logsUse 'show users' to view active sessions and review system logs for any recent shell access eventsAffected if Unexpected or unauthorized shell sessions are present or recorded in logs
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Check for privilege escalation indicatorsReview authentication logs and accounting records for any commands or actions performed at elevated privilege levels beyond the user's normal permissionsAffected if Evidence exists of commands executed at root or privileged levels that were not authorized for the user context
A system is affected if it is running Cisco IOS XE version 16.3(1) with the shell access or privilege exec shell feature enabled, as this is the specific configuration required for the authentication bypass to be exploitable.
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 Cisco IOS XE software update/patch that addresses this vulnerability and disable the shell access feature if not needed, as it is a privileged attack vector.
Fix this in Ios Xe
Scoped from the published advisory
- Consultation2.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2018-15371 — 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-2018-15371 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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