Ios XrOperating system · Cisco
CVE-2021-34771
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 Cisco IOS XR Software CLI could allow an authenticated, local attacker to view more information than their privileges allow. This vulnerability is due to insufficient application of restrictions during the execution of a specific command. An attacker could exploit this vulnerability by running a specific command. A successful exploit could allow the attacker to view sensitive configuration information that their privileges might not otherwise allow them to access.
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 an information disclosure vulnerability in Cisco IOS XR Software's CLI. An authenticated local attacker with limited privileges can execute a specific command that bypasses intended access restrictions, allowing them to view sensitive configuration information they would not normally be permitted to 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 XrOperating system
< 7.3.2CVSS 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
- None
- Availability
- None
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
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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Determine Cisco IOS XR versionExecute 'show version' or 'show install active' from the CLI to identify the installed IOS XR software versionAffected if The version displayed is earlier than 7.3.2 (e.g., 7.3.1, 7.2.x, 7.1.x, etc.)
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Verify user privilege configurationExecute 'show running-config | include username' or 'show privilege' to review user privilege levels configured on the systemAffected if Non-administrator or limited-privilege user accounts exist who can access the CLI
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Identify the specific bypass commandReview command history or system logs for execution of any CLI command that accesses configuration data outside the user's normal authorization scopeAffected if A user with limited privileges executed a command that returned sensitive configuration information they should not normally be able to view
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Check authentication logs for anomaliesExamine system logs (using 'show logging' or 'show audit') for authentication events involving non-privileged users accessing restricted show commandsAffected if Logs show limited-privilege users successfully running commands that bypass access control restrictions
You are affected if your Cisco IOS XR version is earlier than 7.3.2 AND you have non-administrative users with CLI access who can potentially execute the access-restriction-bypassing command.
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.
dbcve · scoped7.3.2
Apply the vendor-provided Cisco IOS XR Software patch when available. Until then, limit local CLI access to trusted personnel only and monitor for unusual command execution patterns.
Cisco IOS XR 7.3.2 or later
- Upgrade Cisco IOS XR to version 7.3.2 or later
- Verify the upgrade by running 'show version' to confirm the new IOS XR version is installed
- After upgrade, verify the vulnerability is remediated by testing the specific command that was previously exposing additional information
- Ensure proper change management and backup procedures are followed before performing the upgrade
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Ios Xr
Scoped from the published advisory
- Consultation4.0 h
- Implementation2.0 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 $3,392.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-34771 — 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-2021-34771 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
- No spam, self-promotion, credentials, or personal data