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Ios Xe Sd WanOperating system · Cisco

CVE-2021-1241

HIGH · 7.5 CVSS v3.1 Published 2021-01-20
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
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
Multiple vulnerabilities in Cisco SD-WAN products could allow an unauthenticated, remote attacker to execute denial of service (DoS) attacks against an affected device. For more information about these vulnerabilities, see the Details section of this advisory.

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 Cisco SD-WAN products allow an unauthenticated, remote attacker to cause denial of service (DoS) conditions against affected devices. The specific vulnerability types and technical details are not provided in the available description, but the attack can be launched without authentication over the network.

MitigationApply Cisco-provided patches or firmware updates for SD-WAN products as soon as they become available. If immediate patching is not possible, consider network segmentation and rate-limiting controls to reduce exposure to unauthenticated remote attackers.

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 Xe Sd WanOperating system
Affected:all versions
Sd Wan FirmwareOperating system
Affected:= 18.3.5= 18.3.8= 18.4.1= 18.4.4= 18.4.5= 19.2.0= 19.2.1= 19.2.2= 19.2.99= 20.1.0
Sd Wan Vsmart Controller FirmwareOperating system
Affected:all versions
Catalyst Sd Wan ManagerApplication
Affected:all versions
Sd Wan Vbond OrchestratorApplication
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
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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 Cisco SD-WAN product in use
    Determine which SD-WAN component is running: Cisco IOS XE SD-WAN, SD-WAN Firmware (vEdge), vSmart Controller, Catalyst SD-WAN Manager (formerly vManage), or vBond Orchestrator. Check the device type or administrative interface for the product name.
    Affected if The device runs any of the five listed SD-WAN products (IOS XE SD-WAN, SD-WAN Firmware, vSmart Controller, SD-WAN Manager, or vBond Orchestrator).
  2. Check the installed SD-WAN Firmware version
    On vEdge devices, run 'show version' or access the administration interface to view the firmware version. Compare the version number against the affected list: 18.3.5, 18.3.8, 18.4.1, 18.4.4, 18.4.5, 19.2.0, 19.2.1, 19.2.2, 19.2.99, 20.1.0.
    Affected if The installed firmware version exactly matches any version in the affected list.
  3. Confirm if running Cisco IOS XE SD-WAN
    On Cisco IOS XE devices with SD-WAN enabled, run 'show sdwan version' or check the system inventory to identify the IOS XE version. Note that ALL versions of Cisco IOS XE SD-WAN are affected.
    Affected if The device runs Cisco IOS XE with SD-WAN capability, regardless of IOS XE version number.
  4. Verify vSmart Controller firmware version
    Access the vSmart Controller CLI and run 'show version' to obtain the firmware version. ALL versions of vSmart Controller Firmware are affected by this CVE.
    Affected if The system runs any version of Cisco SD-WAN vSmart Controller Firmware.
  5. Verify Catalyst SD-WAN Manager version
    Check the SD-WAN Manager (vManage) interface or run 'show version' in the CLI. ALL versions of Cisco Catalyst SD-WAN Manager are affected.
    Affected if The system runs any version of Cisco Catalyst SD-WAN Manager.
  6. Verify vBond Orchestrator version
    Check the vBond Orchestrator CLI with 'show version' or via the administration interface. ALL versions of Cisco SD-WAN vBond Orchestrator are affected.
    Affected if The system runs any version of Cisco SD-WAN vBond Orchestrator.

A system is affected if it runs any of the five listed Cisco SD-WAN products, specifically SD-WAN Firmware versions 18.3.5 through 20.1.0, or any version of IOS XE SD-WAN, vSmart Controller, SD-WAN Manager, or vBond Orchestrator.

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 Cisco-provided patches or firmware updates for SD-WAN products as soon as they become available. If immediate patching is not possible, consider network segmentation and rate-limiting controls to reduce exposure to unauthenticated remote attackers.

Fix this in Ios Xe Sd Wan Scoped from the published advisory
  • Consultation8.0 h
  • Implementation16.0 h
  • Testing12.0 h
  • Review / QA8.0 h
44.0 hours of engineering $7,720
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An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $12,352.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-1241 — 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-2021-1241 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