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AsyncosOperating system · Cisco

CVE-2020-3367

HIGH · 7.8 CVSS v3.1 Published 2020-11-18
Fix available
A fix is available. Upgrade to 11.7.2-011 / 11.8.2-009 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
A vulnerability in the log subscription subsystem of Cisco AsyncOS for the Cisco Secure Web Appliance (formerly Web Security Appliance) could allow an authenticated, local attacker to perform command injection and elevate privileges to root. This vulnerability is due to insufficient validation of user-supplied input for the web interface and CLI. An attacker could exploit this vulnerability by authenticating to the affected device and injecting scripting commands in the scope of the log subscription subsystem. A successful exploit could allow the attacker to execute arbitrary commands on the underlying operating system and elevate privileges to root.

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

A command injection vulnerability exists in the log subscription subsystem of Cisco AsyncOS for the Secure Web Appliance. An authenticated attacker with access to the web interface or CLI can inject arbitrary scripting commands through insufficiently validated user input in the log subscription feature, enabling execution of OS-level commands with root privileges.

MitigationApply the vendor patch from Cisco's security advisory. Until patched, limit administrative access to trusted users only and audit log subscription configuration changes for signs of exploitation.

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
AsyncosOperating system
Affected:< 11.7.2-011>= 11.8.0, < 11.8.2-009>= 12.0.0, < 12.0.2>= 12.5.0, < 12.5.1-011

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 AsyncOS version
    Access the appliance CLI and run the 'version' command, or check the web interface under System Administration > Firmware Upgrade
    Affected if The installed version falls into any of these ranges: < 11.7.2-011, >= 11.8.0 and < 11.8.2-009, >= 12.0.0 and < 12.0.2, >= 12.5.0 and < 12.5.1-011
  2. Confirm log subscription feature is in use
    Access the web interface and navigate to Log Subscriptions or use the CLI command 'logconfig' to list configured subscriptions
    Affected if Log subscription features are actively configured on the appliance
  3. Review log subscription configurations for injected commands
    Inspect each log subscription entry for unexpected parameters, particularly in fields that accept custom input such as filenames, paths, or filter expressions
    Affected if Any subscription contains suspicious characters like semicolons, pipes, backticks, or $() command substitution syntax in input fields
  4. Examine system audit logs for command injection indicators
    Review appliance logs and audit trails for entries containing unusual or unauthorized CLI commands, especially those originating from the web interface or log subscription subsystem
    Affected if Logs show execution of OS commands that were not initiated by legitimate administrators

You are affected if your AsyncOS version is within the vulnerable ranges AND the log subscription feature is accessible to authenticated users, as the injection occurs through that feature.

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.

From vendor data
Upgrade available Upgrade to 11.7.2-011 / 11.8.2-009 / 12.0.2 or later
Fixed in 11.7.2-01111.8.2-00912.0.2
Interim mitigation

Apply the vendor patch from Cisco's security advisory. Until patched, limit administrative access to trusted users only and audit log subscription configuration changes for signs of exploitation.

Fix this in Asyncos Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,130
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,408.

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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-2020-3367 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