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Adaptive Security Appliance SoftwareOperating system · Cisco

CVE-2026-20024

MEDIUM · 5.7 CVSS v3.1 Published 2026-03-04
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
59/100
Remediation priority · Elevated
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 OSPF protocol of Cisco Secure Firewall ASA Software and Cisco Secure FTD Software could allow an authenticated, adjacent attacker to cause an affected device to reload unexpectedly, resulting in a DoS condition. To exploit this vulnerability, the attacker must have the OSPF secret key. This vulnerability is due to heap corruption in OSPF when parsing packets. An attacker could exploit this vulnerability by sending crafted packets to the OSPF service. A successful exploit could allow the attacker to corrupt the heap, causing the affected device to reload, resulting in a DoS condition.

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

Heap corruption vulnerability in the OSPF protocol implementation of Cisco ASA and FTD software allows an authenticated adjacent attacker with the OSPF secret key to send specially crafted OSPF packets that corrupt heap memory, causing the device to reload and result in a denial of service.

MitigationRestrict OSPF adjacency to trusted network segments and rotate the OSPF secret key if compromise is suspected. Apply Cisco 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
Adaptive Security Appliance SoftwareOperating system
Affected:= 9.12.1= 9.12.1.2= 9.12.1.3= 9.12.2= 9.12.2.1= 9.12.2.4= 9.12.2.5= 9.12.2.9= 9.12.3= 9.12.3.2= 9.12.3.7= 9.12.3.9
Secure Firewall Threat DefenseApplication
Affected:= 6.4.0= 6.4.0.1= 6.4.0.2= 6.4.0.3= 6.4.0.4= 6.4.0.5= 6.4.0.6= 6.4.0.7= 6.4.0.8= 6.4.0.9= 6.4.0.10= 6.4.0.11

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

CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:N/I:N/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 device model and software version
    Execute 'show version' on the device CLI or check the management interface for the exact software version
    Affected if Running Cisco ASA Software version 9.12.1, 9.12.1.2, 9.12.1.3, 9.12.2, 9.12.2.1, 9.12.2.4, 9.12.2.5, 9.12.2.9, 9.12.3, 9.12.3.2, 9.12.3.7, or 9.12.3.9, OR Cisco FTD Software version 6.4.0.x (where x is 0-11)
  2. Verify OSPF is enabled on the device
    Execute 'show ospf' or review the running configuration for 'router ospf' process statements
    Affected if OSPF routing process is configured and active on any interface
  3. Confirm OSPF authentication is configured
    Review OSPF interface configuration with 'show run interface' or check OSPF area configuration for 'authentication' or 'message-digest' settings
    Affected if OSPF authentication (secret key or message-digest) is configured on OSPF-enabled interfaces or areas

The device is affected if it runs an exact version from the CVE list, has OSPF enabled, and has OSPF authentication configured with a secret key known to or obtainable by an adjacent attacker.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Restrict OSPF adjacency to trusted network segments and rotate the OSPF secret key if compromise is suspected. Apply Cisco vendor patches when available.

Fix this in Adaptive Security Appliance Software Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,800
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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-2026-20024 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
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