Ios XrOperating system · Cisco
CVE-2021-1485
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 XR Software could allow an authenticated, local attacker to inject arbitrary commands that are executed with root privileges on the underlying Linux operating system (OS) of an affected device. This vulnerability is due to insufficient input validation of commands that are supplied by the user. An attacker could exploit this vulnerability by authenticating to a device and submitting crafted input to an affected command. A successful exploit could allow the attacker to execute commands on the underlying Linux OS 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 · high confidenceCommand injection vulnerability in Cisco IOS XR CLI allows authenticated local attackers to inject arbitrary commands due to insufficient input validation. Successful exploitation grants root-level command execution on the underlying Linux OS of affected network devices.
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 XrOperating system
< 7.3.1CVSS 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 device OS and confirm it's Cisco IOS XRAccess the device CLI and run 'show version' or 'uname -a' to identify the operating system. Confirm the output shows Cisco IOS XR.Affected if The device is NOT running Cisco IOS XR (this CVE only affects IOS XR)
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Determine the installed Cisco IOS XR versionRun 'show version' in the CLI and locate the software version string (typically displayed as XR version number like 7.2.x, 7.3.x, etc.)Affected if Unable to retrieve version information from the device
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Compare installed version against the affected rangeCheck if the version number from step 2 is less than 7.3.1. For example, versions 7.2.1, 7.2.2, 7.2.3, etc. are all below 7.3.1.Affected if The installed version is Cisco IOS XR version 7.3.0 or earlier (any version < 7.3.1)
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Verify local CLI access configurationReview the device configuration for local CLI access settings using 'show running-config' or 'show configuration' commands. Check for line console or line vty configurations.Affected if Local CLI access is enabled (this is the attack vector for authenticated local attackers, though access control is a separate security measure)
The device is affected if it runs Cisco IOS XR version 7.3.0 or earlier (any version below 7.3.1), as only those versions contain the command injection vulnerability in the CLI.
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 data7.3.1
Apply the Cisco IOS XR software update addressing CVE-2021-1485 from the Cisco security advisory. Limit local CLI access to trusted, authorized administrators only.
Fix this in Ios Xr
Scoped from the published advisory
- Consultation4.0 h
- Implementation4.0 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 $3,968.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-1485 — 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-2021-1485 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
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