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Big Ip Protocol Security ModulePlugin / extension · F5

CVE-2009-4420

HIGH · 7.8 CVSS v2.0 Published 2009-12-24
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
87/100
Remediation priority · High
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
Buffer overflow in the bd daemon in F5 Networks BIG-IP Application Security Manager (ASM) 9.4.4 through 9.4.7 and 10.0.0 through 10.0.1, and Protocol Security Manager (PSM) 9.4.5 through 9.4.7 and 10.0.0 through 10.0.1, allows remote attackers to cause a denial of service (crash) via unknown vectors. NOTE: some of these details are obtained from third party information.

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

Buffer overflow vulnerability in the bd daemon of F5 Networks BIG-IP Application Security Manager (ASM) and Protocol Security Manager (PSM) allows remote attackers to cause denial of service via daemon crash. Affected versions include ASM 9.4.4-9.4.7 and 10.0.0-10.0.1, and PSM 9.4.5-9.4.7 and 10.0.0-10.0.1.

MitigationApply F5 security hotfix or upgrade to a patched BIG-IP version; restrict network exposure of management interfaces to reduce attack surface.

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
Big Ip Protocol Security ModulePlugin / extension
Affected:= 10.0.0
Big Ip Application Security ManagerHardware / appliance
Affected:= 9.4.4= 9.4.5= 9.4.6= 9.4.7= 10.0.0= 10.0.1
Big Ip Protocol Security ManagerHardware / appliance
Affected:= 9.4.5= 9.4.6= 9.4.7= 10.0.1

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
Authentication
None
Confidentiality
None
Integrity
None
Availability
Complete

AV:N/AC:L/Au:N/C:N/I:N/A:C

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 if ASM module is installed
    Run 'tmsh list sys module' or check via Configuration Utility under System > Software Management > ISO Image. Alternatively, check 'tmsh show sys module' output for 'asm' module presence.
    Affected if asm module is listed and version matches 9.4.4, 9.4.5, 9.4.6, 9.4.7, 10.0.0, or 10.0.1
  2. Identify if PSM module is installed
    Run 'tmsh list sys module' or check via Configuration Utility under System > Software Management > ISO Image. Look for 'psm' or 'protocol_security' module in the output.
    Affected if psm/protocol_security module is listed and version matches 9.4.5, 9.4.6, 9.4.7, 10.0.0, or 10.0.1
  3. Confirm bd daemon is accessible
    Check if the bd daemon process is running via 'bigstart status bd' or by examining listening ports on management or internal interfaces. The vulnerability is in the bd daemon, which must be accessible for exploitation.
    Affected if bd daemon is running and network-accessible (listening on any interface) on a vulnerable ASM or PSM version
  4. Verify exact product version
    Run 'tmsh show sys software' or check System > Software Management > Installed Plugins in the Configuration Utility to confirm the precise ASM or PSM build number matches one of the affected versions listed.
    Affected if Installed ASM version is 9.4.4-9.4.7 or 10.0.0-10.0.1, OR installed PSM version is 9.4.5-9.4.7 or 10.0.0-10.0.1

You are affected if you have ASM or PSM modules running with versions 9.4.4 through 10.0.1 and the bd daemon is active and network-accessible.

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

Apply F5 security hotfix or upgrade to a patched BIG-IP version; restrict network exposure of management interfaces to reduce attack surface.

Fix this in Big Ip Protocol Security Module 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
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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-2009-4420 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