Data Center Network ManagerApplication · Cisco
CVE-2020-3518
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-based management interface of Cisco Data Center Network Manager (DCNM) Software could allow an authenticated, remote attacker to conduct a cross-site scripting (XSS) attack against a user of the interface of the affected software. The vulnerability exists because the web-based management interface does not properly validate user-supplied input. An attacker could exploit this vulnerability by persuading a user of the interface to click a crafted link. A successful exploit could allow the attacker to execute arbitrary script code in the context of the affected interface or access sensitive, browser-based information.
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 confidenceA stored cross-site scripting (XSS) vulnerability in Cisco Data Center Network Manager (DCNM) allows authenticated attackers to inject malicious JavaScript through unsanitized user input. When other users click the crafted link, the attacker's script executes in their browser context, potentially stealing session tokens or sensitive data.
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
< 11.4\(1\)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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Verify Cisco DCNM is installedCheck if Cisco Data Center Network Manager is present in your environment by looking for the DCNM installation directory or running processes. Common installation paths on Linux: /opt/cisco/dcm or /usr/local/cisco/dcm. On Windows: C:\Program Files\Cisco\DCNM.Affected if DCNM is not installed in your environment, you are not affected by this vulnerability.
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Determine the installed DCNM versionLog into the DCNM web interface and navigate to the About or Help section, or run 'dcm/bin/dcmctl -version' from the installation directory. Alternatively, check the file /opt/cisco/dcm/RELEASE if using default Linux installation paths.Affected if The installed version is lower than 11.4(1). If you are running 11.4(1) or higher, you are not affected.
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Confirm the DCNM web interface is accessibleAttempt to access the DCNM web interface via browser at https://[hostname]/ or check if ports 80, 443, or 8080 are listening on the DCNM server using 'netstat -an | grep -E ':(80|443|8080)' or equivalent.Affected if The web interface is accessible to users, which is required for the XSS to be triggered when other users click injected links.
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Identify if authentication is enabled and users existCheck if DCNM authentication is configured by examining the user settings in the DCNM web interface or by reviewing the users.xml or similar user configuration files in the DCNM installation directory.Affected if Authenticated user accounts exist in DCNM, meaning an attacker could potentially inject the malicious script through unsanitized input fields.
You are affected if DCNM is installed with a version lower than 11.4(1), the web interface is accessible, and authenticated users can interact with input fields that are not properly sanitized.
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 data11.4
Apply Cisco's official security patch for CVE-2020-3518. Until patched, restrict web interface access to trusted users and educate users about avoiding untrusted links.
Fix this in Data Center Network Manager
Scoped from the published advisory
- Consultation3.0 h
- Implementation6.0 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 $4,224.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-3518 — 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-2020-3518 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