AsyncosOperating system · Cisco

CVE-2020-3546

MEDIUM · 5.3 CVSS v3.1 Published 2020-09-04
Fix available
A fix is available. Upgrade to after 13.5.1 or later.
See remediation →
62/100
Remediation priority · Elevated
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
A vulnerability in the web-based management interface of Cisco AsyncOS software for Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to access sensitive information on an affected device. The vulnerability is due to insufficient validation of requests that are sent to the web-based management interface. An attacker could exploit this vulnerability by sending a crafted request to the interface of an affected device. A successful exploit could allow the attacker to obtain the IP addresses that are configured on the internal interfaces of the affected device. There is a workaround that addresses this vulnerability.

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

A vulnerability in the web-based management interface of Cisco AsyncOS for Email Security Appliance allows unauthenticated remote attackers to obtain internal interface IP addresses due to insufficient request validation. Attackers exploit this by sending crafted requests to the management interface.

MitigationApply the Cisco-provided workaround (typically restricting access to the management interface via ACLs or disabling external access) or apply the vendor patch 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
AsyncosOperating system
Affected:<= 13.5.1

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
Low
Integrity
None
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

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. Confirm Cisco Email Security Appliance model
    Log into the device CLI and run the command 'version' or 'show version' to identify the hardware model (ESA - Email Security Appliance)
    Affected if Device is a Cisco Email Security Appliance (ESA)
  2. Check AsyncOS version
    Run the command 'version' in the CLI and locate the AsyncOS version number in the output
    Affected if AsyncOS version is 13.5.1 or lower
  3. Verify web-based management interface is enabled
    Run 'list' or check the interface configuration to confirm the web GUI (HTTP/HTTPS) listener is configured on the management interface
    Affected if Web management interface (GUI) is enabled and listening
  4. Assess management interface network exposure
    Check ACLs or interface bindings to determine if the web management interface is reachable from untrusted networks (external IPs)
    Affected if Management interface is accessible from untrusted/external networks

Your environment is affected if you are running Cisco Email Security Appliance with AsyncOS version 13.5.1 or lower and the web-based management interface is network-accessible to untrusted parties.

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 a release after 13.5.1
Interim mitigation

Apply the Cisco-provided workaround (typically restricting access to the management interface via ACLs or disabling external access) or apply the vendor patch when available.

Fix this in Asyncos Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,240
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,984.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2020-3546 — 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 sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2020-3546 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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