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Sd Wan VmanageApplication · Cisco

CVE-2021-1535

MEDIUM · 5.3 CVSS v3.1 Published 2021-05-06
Fix available
A fix is available. Upgrade to 20.5.1 or later.
See remediation →
62/100
Remediation priority · Elevated
Remotely reachable No privileges 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
A vulnerability in the cluster management interface of Cisco SD-WAN vManage Software could allow an unauthenticated, remote attacker to view sensitive information on an affected system. To be affected by this vulnerability, the Cisco SD-WAN vManage Software must be in cluster mode. This vulnerability is due to the absence of authentication for sensitive information in the cluster management interface. An attacker could exploit this vulnerability by sending a crafted request to the cluster management interface of an affected system. A successful exploit could allow the attacker to allow the attacker to view sensitive information on the affected system.

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 confidence

Cisco SD-WAN vManage Software contains a vulnerability in its cluster management interface where authentication is not enforced for sensitive information. An unauthenticated remote attacker can send crafted HTTP requests to the cluster management interface to view sensitive data without credentials. Only systems running in cluster mode are affected.

MitigationApply the vendor patch from Cisco for CVE-2021-1535. As an interim control, restrict network access to the cluster management interface using firewalls or network segmentation to prevent unauthorized external 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
Sd Wan VmanageApplication
Affected:< 20.5.1

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
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/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 checks

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

  1. Confirm Cisco SD-WAN vManage is installed
    Identify if the Cisco vManage software is running on the system. This is typically a dedicated vManage virtual appliance or hardware. Check system inventory, running processes, or consult documentation to confirm vManage presence.
    Affected if vManage software is not present on the system.
  2. Determine if vManage is running in cluster mode
    Check the vManage cluster configuration or status. This can be done via the vManage admin interface, CLI show commands, or by reviewing the cluster setup documentation. Look for evidence that multiple vManage nodes are configured to operate as a cluster.
    Affected if The system is NOT running in cluster mode - only cluster mode deployments are affected by this vulnerability.
  3. Check the installed vManage version
    Retrieve the installed vManage software version. This is typically available via the vManage web UI under Administration > Settings, or via CLI commands such as 'show version' or 'request software version'. Compare the version number against the affected range.
    Affected if The installed version is prior to 20.5.1 (for example, 20.3.x, 20.4.x, or earlier). Versions 20.5.1 and later are not affected.

A system is affected only if it is running Cisco SD-WAN vManage in cluster mode with a version prior to 20.5.1.

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
Upgrade available Upgrade to 20.5.1 or later
Fixed in 20.5.1
Interim mitigation

Apply the vendor patch from Cisco for CVE-2021-1535. As an interim control, restrict network access to the cluster management interface using firewalls or network segmentation to prevent unauthorized external access.

Fix this in Sd Wan Vmanage Scoped from the published advisory
  • Consultation4.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,820
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,912.

Scan for this in your stack

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dbcve dependency scanner

Check whether your project pulls in CVE-2021-1535 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

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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-2021-1535 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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