Application Policy Infrastructure ControllerApplication · Cisco
CVE-2021-1578
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 an API endpoint of Cisco Application Policy Infrastructure Controller (APIC) and Cisco Cloud Application Policy Infrastructure Controller (Cloud APIC) could allow an authenticated, remote attacker to elevate privileges to Administrator on an affected device. This vulnerability is due to an improper policy default setting. An attacker could exploit this vulnerability by using a non-privileged credential for Cisco ACI Multi-Site Orchestrator (MSO) to send a specific API request to a managed Cisco APIC or Cloud APIC device. A successful exploit could allow the attacker to obtain Administrator credentials on the affected device.
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 vulnerability in the API endpoint of Cisco APIC and Cisco Cloud APIC allows an authenticated attacker with non-privileged credentials for Cisco ACI Multi-Site Orchestrator to send specific API requests that elevate their privileges to Administrator level. The root cause is an improper policy default setting that grants excessive permissions through the API, allowing the attacker to obtain Administrator credentials on affected devices.
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
Application Policy Infrastructure ControllerApplication
>= 5.0, <= 5.1\(3e\)= 5.0\(2h\)
Cloud Application Policy Infrastructure ControllerApplication
>= 5.0, <= 5.1\(3e\)= 5.0\(2h\)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
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/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 checksWork through these to decide whether this CVE applies to you.
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Check installed APIC versionLog into the Cisco APIC GUI, navigate to System > Controllers, or run 'show version' via CLI. For Cloud APIC, check via the Cloud APIC dashboard or API.Affected if Version is 5.0(2h) or any version from 5.0 up to and including 5.1(3e)
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Confirm API endpoint accessibilityVerify that the REST API is reachable on the APIC (typically port 443). Test with a basic authenticated request to the API URL (e.g., https://<apic-ip>/api/ ).Affected if API endpoint is exposed and accepts authenticated requests from non-privileged users
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Identify non-privileged MSO credentialsReview Cisco ACI Multi-Site Orchestrator (MSO) user accounts. Check for users with non-Administrator roles (e.g., read-only, tenant-admin) that have API access privileges.Affected if Non-privileged MSO user accounts exist with API access capabilities
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Check for excessive API permissions in policyReview the default policy settings for API permissions. Inspect the role-based access control (RBAC) configuration for MSO users, specifically looking for default policies that grant elevated API permissions beyond the intended role level.Affected if Default policy grants excessive permissions to non-privileged API users, allowing privilege escalation to Administrator level
You are affected if your APIC or Cloud APIC version falls within 5.0 through 5.1(3e) or equals 5.0(2h), the API is accessible, and non-privileged users have API access with default policy settings that allow privilege escalation.
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 Cisco security update for CVE-2021-1578 to affected Cisco APIC and Cloud APIC devices. If no patch is available, review and restrict API permissions for non-privileged MSO credentials until the vendor patch can be deployed.
Fix this in Application Policy Infrastructure Controller
Scoped from the published advisory
- Consultation3.0 h
- Implementation4.0 h
- Testing3.0 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 $3,408.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-1578 — 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-2021-1578 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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- Version or environment caveats, and links to real fixes
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