dbcve.org
Umbrella Virtual ApplianceApplication · Cisco

CVE-2022-20773

HIGH · 7.5 CVSS v3.1 Published 2022-04-21
Fix available
A fix is available. Upgrade to 3.3.2 or later.
See remediation →
82/100
Remediation priority · High
Remotely reachable No privileges

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
A vulnerability in the key-based SSH authentication mechanism of Cisco Umbrella Virtual Appliance (VA) could allow an unauthenticated, remote attacker to impersonate a VA. This vulnerability is due to the presence of a static SSH host key. An attacker could exploit this vulnerability by performing a man-in-the-middle attack on an SSH connection to the Umbrella VA. A successful exploit could allow the attacker to learn the administrator credentials, change configurations, or reload the VA. Note: SSH is not enabled by default on the Umbrella VA.

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

Cisco Umbrella Virtual Appliance contains a static (hardcoded) SSH host key in its key-based authentication mechanism. This allows an attacker performing a man-in-the-middle attack on SSH connections to impersonate the VA and intercept credentials or commands. An exploited attacker can steal admin credentials, modify configurations, or force a VA reload.

MitigationApply the Cisco patch for this vulnerability which replaces the static host key with dynamically-generated unique keys. Until patched, avoid enabling SSH on Umbrella VA deployments and verify SSH connections are not subject to interception.

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
Umbrella Virtual ApplianceApplication
Affected:< 3.3.2

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

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/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 the installed product
    Confirm the system is running Cisco Umbrella Virtual Appliance by checking the system inventory, virtual machine details, or running 'show version' if accessible on the VA CLI
    Affected if The system is not a Cisco Umbrella Virtual Appliance
  2. Check the installed version
    Access the VA CLI or management interface and run the command to display the software version (such as 'show version' or check the management dashboard)
    Affected if The installed version is lower than 3.3.2 (for example, 3.3.1, 3.3.0, or earlier)
  3. Verify if SSH is enabled
    Check the VA configuration settings via the management interface or CLI for SSH service status (look for 'ssh' or 'sshd' in running config or service status)
    Affected if SSH service is enabled and running on the Virtual Appliance
  4. Inspect SSH host key configuration
    Examine the SSH server configuration files (typically /etc/ssh/sshd_config or similar) and the host key files in /etc/ssh/ for the host keys. Check if the same host key is present across multiple VA instances or persists across reinstalls
    Affected if A static or hardcoded SSH host key is in use (same key found across different VA deployments or after reinstallation)

You are affected if you are running Cisco Umbrella Virtual Appliance version lower than 3.3.2 with SSH enabled and a static host key present in the configuration.

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 3.3.2 or later
Fixed in 3.3.2
Interim mitigation

Apply the Cisco patch for this vulnerability which replaces the static host key with dynamically-generated unique keys. Until patched, avoid enabling SSH on Umbrella VA deployments and verify SSH connections are not subject to interception.

Recommended fix High confidence

3.3.2

  1. 1. Back up the current Umbrella Virtual Appliance configuration before upgrading.
  2. 2. Download Cisco Umbrella Virtual Appliance version 3.3.2 from the Cisco download portal or your Cisco contract channel.
  3. 3. Schedule a maintenance window since the VA will require a reboot during upgrade.
  4. 4. Upgrade the Umbrella Virtual Appliance to version 3.3.2 following the standard VA upgrade procedure.
  5. 5. After upgrade completes, verify the VA is operational and connected to the Umbrella dashboard.
  6. 6. Since the vulnerability could have allowed credential exposure, immediately change the administrator SSH credentials as a precaution.
  7. 7. If SSH was enabled, verify SSH is working correctly with the new dynamic host keys.
Caveat Standard VA upgrade requiring maintenance window and configuration backup; ensure proper rollback plan is in place

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

Fix this in Umbrella Virtual Appliance Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,490
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,984.

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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-2022-20773 in production — separate from our analysis above.

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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