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Steelcentral Appinternals Dynamic Sampling AgentApplication · Riverbed

CVE-2021-42854

CRITICAL · 9.8 CVSS v3.1 Published 2022-03-10
Fix available
A fix is available. Upgrade to 11.8.8 / 12.13.0 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

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 · unedited
It was discovered that the SteelCentral AppInternals Dynamic Sampling Agent's (DSA) PluginServlet has directory traversal vulnerabilities at the "/api/appInternals/1.0/plugin/pmx" API. The affected endpoint does not have any input validation of the user's input that allows a malicious payload to be injected.

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 confidence

The SteelCentral AppInternals Dynamic Sampling Agent's PluginServlet contains directory traversal vulnerabilities in the /api/appInternals/1.0/plugin/pmx API endpoint. The affected endpoint fails to validate or sanitize user-supplied input, allowing attackers to use path traversal sequences (e.g., ../../) to access arbitrary files and directories outside the web root.

MitigationImplement strict input validation and sanitization on the plugin API endpoint to reject path traversal sequences. Apply vendor patches when available and restrict file system access permissions for the affected service.

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
Steelcentral Appinternals Dynamic Sampling AgentApplication
Affected:>= 11.0.0, < 11.8.8>= 12.0.0, < 12.13.0= 10.0.0

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
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify if SteelCentral AppInternals Dynamic Sampling Agent is installed
    Locate the installation directory or check running processes for the Dynamic Sampling Agent service (commonly named AppInternals or SteelCentral agent components)
    Affected if The software is present on the system
  2. Determine the installed version
    Check the product version using its built-in version command, about dialog, or version file in the installation directory
    Affected if The installed version matches 10.0.0, or falls within 11.0.0 to 11.8.7, or 12.0.0 to 12.12.9
  3. Verify the PluginServlet API endpoint is accessible
    Confirm the web service is running and the /api/appInternals/1.0/plugin/pmx endpoint is reachable (check if port 8080 or the configured HTTP port is open and responding)
    Affected if The web interface and API endpoint are accessible
  4. Check if the agent service is running with elevated privileges
    Inspect the service account or process user context under which the Dynamic Sampling Agent runs
    Affected if The service runs with administrative or file system access beyond its operational directory
  5. Inspect network exposure of the management interface
    Review firewall rules and network binding configuration to determine if the API port is exposed to untrusted networks
    Affected if The /api/appInternals endpoint is reachable from outside the local host or trusted network

A system is affected if it runs a vulnerable version (10.0.0, 11.0.0-11.8.7, or 12.0.0-12.12.9) of SteelCentral AppInternals Dynamic Sampling Agent with the web API accessible to potential attackers.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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.

dbcve · scoped
Upgrade available Upgrade to 11.8.8 / 12.13.0 or later
Fixed in 11.8.812.13.0
Interim mitigation

Implement strict input validation and sanitization on the plugin API endpoint to reject path traversal sequences. Apply vendor patches when available and restrict file system access permissions for the affected service.

Recommended fix High confidence

Upgrade to SteelCentral AppInternals DSA version 11.8.8+ (11.x line) or 12.13.0+ (12.x line), with preference for the latest stable 12.x release

  1. 1. Identify the currently installed version of SteelCentral AppInternals Dynamic Sampling Agent
  2. 2. For DSA versions 11.0.0 through 11.7.x: upgrade to version 11.8.8 or later in the 11.x release line
  3. 3. For DSA versions 12.0.0 through 12.12.x: upgrade to version 12.13.0 or later in the 12.x release line
  4. 4. For DSA version 10.0.0: upgrade to at least version 11.8.8 or version 12.13.0 (preferably the latest stable 12.x release)
  5. 5. After upgrading, verify the fix by testing that the /api/appInternals/1.0/plugin/pmx endpoint properly validates input and rejects directory traversal attempts
  6. 6. Confirm the upgrade was successful by checking the DSA agent version matches the target fixed release
Caveat Review release notes for 11.8.8 and 12.13.0 for any compatibility changes or deprecated features before upgrading production agents

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Steelcentral Appinternals Dynamic Sampling Agent Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA3.0 h
21.0 hours of engineering $3,680
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-42854 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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  • No spam, self-promotion, credentials, or personal data