Ios XeOperating system · Cisco
CVE-2019-12671
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 CLI of Cisco IOS XE Software could allow an authenticated, local attacker to gain shell access on an affected device and execute commands on the underlying operating system (OS). The vulnerability is due to insufficient enforcement of the consent token in authorizing shell access. An attacker could exploit this vulnerability by authenticating to the CLI and requesting shell access on an affected device. A successful exploit could allow the attacker to gain shell access on the affected device and execute commands on the underlying OS.
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 confidenceCisco IOS XE Software contains a vulnerability in its CLI where insufficient enforcement of consent token mechanisms allows an authenticated local attacker to bypass authorization checks and gain shell access to the underlying operating system. This enables execution of arbitrary OS-level commands, representing a privilege escalation from CLI user to shell/root.
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
= 16.11.1CVSS 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:3.1/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 IOS XE versionRun 'show version' or 'show version | include Version' from the CLI to retrieve the installed IOS XE version numberAffected if The displayed version is exactly 16.11.1 (the only affected version per this CVE)
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Confirm the device runs IOS XE softwareVerify that the output of 'show version' indicates 'IOS XE' rather than classic IOS or other platformsAffected if The device is confirmed to be running Cisco IOS XE software and the version is 16.11.1
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Verify shell access methods are availableCheck for available shell access methods by examining the output of 'show platform' or attempting to determine if 'shell' or 'guestshell' commands are accessible from user EXEC or privileged EXEC modeAffected if Shell access (via 'enable shell', 'guestshell', or similar mechanisms) is reachable from the CLI without additional authentication beyond normal login
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Review authorization and consent token configurationExamine the current AAA and authorization configuration using 'show running-config | include aaa|authorization' to see how consent tokens and privilege escalation are configuredAffected if Authorization for shell access relies on consent token mechanisms that may not be properly enforced (vulnerability present)
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Check for recent privileged EXEC accessReview logs and session history using 'show logging' or 'show users' to look for recent privilege escalation events or shell session initiations that were not performed by authorized administratorsAffected if There are unauthorized privilege escalation events or shell sessions recorded in logs or active user sessions
The environment is affected if the device runs exactly Cisco IOS XE version 16.11.1 and shell access can be obtained from the CLI without proper authorization enforcement.
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 relevant Cisco IOS XE software update or patch from Cisco's official advisory. Until patched, strictly limit physical and administrative access to affected devices and monitor for unauthorized shell access attempts.
Fix this in Ios Xe
Scoped from the published advisory
- Consultation3.0 h
- Implementation6.0 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 $4,224.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2019-12671 — 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-2019-12671 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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