Data Center Network ManagerApplication · Cisco
CVE-2020-3520
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 Cisco Data Center Network Manager (DCNM) Software could allow an authenticated, local attacker to obtain confidential information from an affected device. The vulnerability is due to insufficient protection of confidential information on an affected device. An attacker at any privilege level could exploit this vulnerability by accessing local filesystems and extracting sensitive information from them. A successful exploit could allow the attacker to view sensitive data, which they could use to elevate their privilege.
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 confidenceCisco DCNM software contains an information disclosure vulnerability where authenticated local attackers can access local filesystems and extract sensitive information due to insufficient protection of confidential data. This can lead to privilege escalation.
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
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/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 checksWork through these to decide whether this CVE applies to you.
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Identify if Cisco DCNM is installedLocate the Cisco Data Center Network Manager installation on the system. This is typically found in /opt or /usr directory on Linux systems, or C:\Program Files on Windows. Look for directories or services named 'dcnm', 'Data Center Network Manager', or 'CiscoDCNM'.Affected if Cisco DCNM software is present on the system
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Determine the installed DCNM versionRun the command to check the DCNM version. On Linux, this may be 'dcnm -version' or checking /opt/dcm/VERSION file if installed in /opt. On Windows, check the version through the Windows Programs feature or look for a version file in the installation directory.Affected if The installed version is lower than 11.4(1)
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Verify the DCNM web interface or API is accessibleCheck if the DCNM web interface (typically ports 8443 or 443) or REST API is listening and accessible on the network. This is the attack surface for the vulnerability.Affected if The DCNM web interface or API is accessible over the network
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Check for local filesystem access through DCNMReview DCNM configuration and logs for any file upload, file download, or file access features that may be exposed through the web interface. Look for endpoints that accept file paths or allow directory traversal.Affected if Features allowing local filesystem access are enabled or exposed in DCNM
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Review user access controlsExamine the DCNM user management to determine if non-administrator local users exist or if the system allows local authentication. The vulnerability is exploitable by authenticated local attackers.Affected if Local user authentication is enabled or there are users with access to DCNM beyond the administrator account
The environment is affected if Cisco DCNM is installed with a version lower than 11.4(1) and the web interface or local user authentication is accessible.
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 the relevant Cisco security patch for DCNM. Until patched, limit local access to trusted administrators and monitor for unauthorized access to local filesystem resources.
Fix this in Data Center Network Manager
Scoped from the published advisory
- Consultation2.0 h
- Implementation4.0 h
- Testing2.0 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 $2,848.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-3520 — 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-2020-3520 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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