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Ios XeOperating system · Cisco

CVE-2021-1454

MEDIUM · 6.7 CVSS v3.1 Published 2021-03-24
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
69/100
Remediation priority · Elevated
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 CLI of Cisco IOS XE SD-WAN Software could allow an authenticated, local attacker to access the underlying operating system with root privileges. These vulnerabilities are due to insufficient input validation of certain CLI commands. An attacker could exploit these vulnerabilities by authenticating to the device and submitting crafted input to the CLI. The attacker must be authenticated as an administrative user to execute the affected commands. A successful exploit could allow the attacker to access the underlying operating system with root privileges.

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 CLI of Cisco IOS XE SD-WAN Software allow an authenticated administrative user to execute malicious input through certain CLI commands, bypassing normal access controls to gain root privileges on the underlying operating system. The root cause is insufficient input validation in the CLI parser.

MitigationApply the relevant Cisco security updates/patches for IOS XE SD-WAN Software. Ensure administrative accounts follow least-privilege principles and monitor for unauthorized 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
Affected:all versions
Ios Xe Sd WanOperating system
Affected:all versions

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:3.1/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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify the IOS XE version and SD-WAN configuration
    Run 'show version' and 'show sdwan version' commands to confirm the IOS XE version and whether SD-WAN features are enabled
    Affected if The device runs any version of Cisco IOS XE with SD-WAN software features configured
  2. Verify CLI access exposure
    Review the device's management access configuration using 'show ip http server status' and 'show line' to determine if CLI is accessible from untrusted networks
    Affected if CLI is reachable from outside management networks or the internet without proper access controls
  3. Check for unauthorized root-level access
    Run 'show users' and 'show privilege' to identify any sessions with elevated privileges, and review system logs for commands executed by users with privilege level 15
    Affected if Unexpected sessions exist with root/privilege 15 access or unusual commands appear in logs
  4. Inspect for suspicious CLI commands in logs
    Search system logs (using 'show logging' or external syslog) for CLI commands that may indicate exploitation attempts, particularly those attempting shell escape or privilege escalation
    Affected if Logs contain unusual CLI commands, especially those involving shell access or system commands outside normal operations
  5. Review user account activity
    Use 'show users history' and examine authentication logs to identify administrative accounts that may have been used for unauthorized access
    Affected if Administrative accounts show activity from unexpected sources or at times when legitimate administrators were not logged in

A system is affected if it runs Cisco IOS XE with SD-WAN functionality enabled and has CLI accessible to authenticated administrators, making it vulnerable to privilege escalation attacks.

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.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the relevant Cisco security updates/patches for IOS XE SD-WAN Software. Ensure administrative accounts follow least-privilege principles and monitor for unauthorized access.

Fix this in Ios Xe Scoped from the published advisory
  • Consultation3.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,770
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Scan for this in your stack

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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-2021-1454 in production — separate from our analysis above.

No notes yet

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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