Data Center Network ManagerApplication · Cisco
CVE-2021-1253
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 · uneditedMultiple vulnerabilities in the web-based management interface of Cisco Data Center Network Manager (DCNM) could allow a remote attacker with network-operator privileges to conduct a cross-site scripting (XSS) attack or a reflected file download (RFD) attack against a user of the interface. 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 · high confidenceMultiple vulnerabilities in Cisco DCNM's web-based management interface allow an authenticated attacker with network-operator privileges to conduct cross-site scripting (XSS) or reflected file download (RFD) attacks against other users of the interface.
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
Data Center Network ManagerApplication
< 11.5\(1\)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
- Low
- User interaction
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/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 installed DCNM versionAccess the DCNM web management interface and navigate to the About or Administration section to view the software version, or use the CLI command 'dcnm_version' if availableAffected if The displayed version is any version prior to 11.5(1)
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Confirm web-based management interface is activeAttempt to access the DCNM web interface URL (typically https://<device-ip>/dcnm) to verify it respondsAffected if The web interface is accessible and responds to HTTP/HTTPS requests
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Verify network-operator role existsCheck the DCNM user management section to see if any accounts are assigned the network-operator roleAffected if At least one user account with network-operator privileges exists in the system
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Check for existing user sessionsReview DCNM session logs or active session information if available through the administration interfaceAffected if Multiple users with varying privilege levels are actively using the web interface simultaneously
The environment is affected if Cisco Data Center Network Manager version is below 11.5(1) and the web-based management interface is accessible to authenticated users with network-operator privileges.
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 data11.5
Apply the relevant Cisco patches for DCNM as specified in the official advisory; until patched, monitor for suspicious user sessions and educate users about not clicking untrusted links.
Fix this in Data Center Network Manager
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-2021-1253 — 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-2021-1253 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
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