Sd Wan FirmwareOperating system · Cisco
CVE-2020-3405
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 web UI of Cisco SD-WAN vManage Software could allow an authenticated, remote attacker to gain read and write access to information that is stored on an affected system. The vulnerability is due to improper handling of XML External Entity (XXE) entries when parsing certain XML files. An attacker could exploit this vulnerability by persuading a user to import a crafted XML file with malicious entries. A successful exploit could allow the attacker to read and write files within the affected application.
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 confidenceThe vulnerability is an XML External Entity (XXE) injection flaw in Cisco SD-WAN vManage's web UI. An authenticated attacker can exploit this by tricking a user into importing a crafted XML file containing malicious XXE entries. This allows the attacker to read and write files on the affected system due to improper handling of external entity references during XML parsing.
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 FirmwareOperating system
<= 19.2.2CVSS 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
- Network
- Complexity
- Low
- Privileges
- Low
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/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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Identify Cisco SD-WAN vManage installationLocate the vManage web UI interface or check system inventory for Cisco SD-WAN vManage software. Confirm the device is running the vManage management component.Affected if System is not Cisco SD-WAN vManage - not applicable.
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Determine vManage firmware versionAccess vManage via CLI with 'show version' or via the web UI under Administration > Software Management to view the installed firmware version number.Affected if Firmware version is 19.2.2 or lower - vulnerable to CVE-2020-3405.
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Verify XML import feature accessibilityCheck if the XML file import functionality is available in the vManage web UI. Navigate to Configuration > Templates or related import features to confirm XML import capability is present and not administratively disabled.Affected if XML import feature is enabled and accessible to authenticated users - potential attack vector exists.
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Review logs for XML import activityExamine vManage system logs and audit logs for recent XML file import events. Look for import operations around the time of suspected compromise or for imports from untrusted sources.Affected if Suspicious or unauthorized XML import events are found in logs - possible exploitation attempt.
Environment is affected if running Cisco SD-WAN vManage firmware version 19.2.2 or lower with the XML file import feature accessible to authenticated users.
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 dataApply the relevant Cisco security patch for CVE-2020-3405. Until patched, restrict or disable XML file import functionality in vManage and monitor for suspicious import activity.
Fix this in Sd Wan Firmware
Scoped from the published advisory
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-3405 — 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-2020-3405 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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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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