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Steelcentral Appinternals Dynamic Sampling AgentApplication · Riverbed

CVE-2021-42855

HIGH · 7.8 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 →
80/100
Remediation priority · High
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 (DSA) uses the ".debug_command.config" file to store a json string that contains a list of IDs and pre-configured commands. The config file is subsequently used by the "/api/appInternals/1.0/agent/configuration" API to map the corresponding ID to a command to be executed.

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 · moderate confidence

The SteelCentral AppInternals DSA stores pre-configured command mappings in a .debug_command.config file, which the /api/appInternals/1.0/agent/configuration API uses to execute commands based on ID lookups. This design allows arbitrary command execution through the API endpoint by manipulating the config file or the ID-to-command mapping.

MitigationRestrict or remove the .debug_command.config file and disable the /api/appInternals/1.0/agent/configuration endpoint if not required for operation, or apply vendor patches when available.

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
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/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 checks

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

  1. Identify installed DSA version
    Locate the SteelCentral AppInternals DSA installation and check its version number (typically via installer, service properties, or version file in the installation directory). Compare the version to the affected ranges: 10.0.0, or >= 11.0.0 but < 11.8.8, or >= 12.0.0 but < 12.13.0.
    Affected if The installed version matches any of the affected ranges.
  2. Locate the .debug_command.config file
    Search the DSA installation directory and related directories for a file named .debug_command.config. This file stores command mappings used by the agent configuration API.
    Affected if The .debug_command.config file exists on the system.
  3. Verify API endpoint accessibility
    Check if the /api/appInternals/1.0/agent/configuration API endpoint is exposed and accessible (typically on the DSA server port). This endpoint reads the command mappings from the config file.
    Affected if The API endpoint is reachable without additional authentication or is accessible to untrusted users.
  4. Review command mappings in config
    Examine the contents of the .debug_command.config file to see what commands are mapped to which IDs. Look for any mappings that could allow arbitrary command execution or unexpected commands.
    Affected if The config file contains command mappings that were not intentionally configured by administrators, or contains dangerous commands mapped to accessible IDs.

A system is affected if it runs a vulnerable DSA version AND has the .debug_command.config file present with the API endpoint accessible, allowing potential unauthorized command execution through the configuration API.

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

Restrict or remove the .debug_command.config file and disable the /api/appInternals/1.0/agent/configuration endpoint if not required for operation, or apply vendor patches when available.

Recommended fix High confidence

Upgrade to 11.8.8 (for 11.x deployments) or 12.13.0 (for 12.x deployments)

  1. 1. Identify the current version of SteelCentral AppInternals Dynamic Sampling Agent installed in your environment
  2. 2. If version is 10.0.0, upgrade to version 11.8.8 or later (11.x LTS)
  3. 3. If version is 11.0.0 through 11.7.x, upgrade to version 11.8.8 or later
  4. 4. If version is 12.0.0 through 12.12.x, upgrade to version 12.13.0 or later
  5. 5. After upgrade, verify the .debug_command.config file is no longer accessible via the API endpoint
  6. 6. Test that the /api/appInternals/1.0/agent/configuration API functions correctly with the patched version
  7. 7. Confirm agent is reporting to the SteelCentral controller without errors
Caveat Review release notes for any breaking changes between current and target version before upgrading

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
  • Consultation2.0 h
  • Implementation3.0 h
  • Testing2.0 h
  • Review / QA1.0 h
8.0 hours of engineering $1,420
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,272.

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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-2021-42855 in production — separate from our analysis above.

No notes yet

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What this is

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.

What belongs here
  • 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