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Big Ip Access Policy ManagerApplication · F5

CVE-2025-21087

HIGH · 7.5 CVSS v3.1 Published 2025-02-05
Fix available
A fix is available. Upgrade to 16.1.6 / 17.1.2 or later.
See remediation →
84/100
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
When Client or Server SSL profiles are configured on a Virtual Server, or DNSSEC signing operations are in use, undisclosed traffic can cause an increase in memory and CPU resource utilization. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated

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 denial-of-service vulnerability in F5 products allows remote attackers to cause excessive memory and CPU consumption by sending undisclosed traffic patterns to Virtual Servers configured with Client or Server SSL profiles, or to systems performing DNSSEC signing operations. The attack can lead to service degradation or unavailability due to resource exhaustion.

MitigationApply the vendor-supplied patch when available. In the interim, implement rate limiting, traffic filtering, or GeoIP blocking on affected Virtual Servers to mitigate abnormal traffic patterns.

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 Access Policy ManagerApplication
Affected:>= 15.1.0, <= 15.1.10>= 16.1.0, < 16.1.6>= 17.1.0, < 17.1.2
Big Ip Advanced Firewall ManagerApplication
Affected:>= 15.1.0, <= 15.1.10>= 16.1.0, < 16.1.6>= 17.1.0, < 17.1.2
Big Ip Advanced Web Application FirewallApplication
Affected:>= 15.1.0, <= 15.1.10>= 16.1.0, < 16.1.6>= 17.1.0, < 17.1.2
Big Ip AnalyticsApplication
Affected:>= 15.1.0, <= 15.1.10>= 16.1.0, < 16.1.6>= 17.1.0, < 17.1.2
Big Ip Application Acceleration ManagerApplication
Affected:>= 15.1.0, <= 15.1.10>= 16.1.0, < 16.1.6>= 17.1.0, < 17.1.2
Big Ip Application Security ManagerApplication
Affected:>= 15.1.0, <= 15.1.10>= 16.1.0, < 16.1.6>= 17.1.0, < 17.1.2
Big Ip Application Visibility And ReportingApplication
Affected:>= 15.1.0, <= 15.1.10>= 16.1.0, < 16.1.6>= 17.1.0, < 17.1.2
Big Ip Automation ToolchainApplication
Affected:>= 15.1.0, <= 15.1.10>= 16.1.0, < 16.1.6>= 17.1.0, < 17.1.2

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

CVSS:3.1/AV:N/AC:L/PR:N/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 F5 Big IP software version
    Run 'tmsh show sys version' in the Traffic Management Shell (TMSH) or check the version displayed in the web UI header. Compare the version number to the affected ranges: 15.1.0-15.1.10, 16.1.0-16.1.5, or 17.1.0-17.1.1.
    Affected if The installed version falls within any of the affected version ranges.
  2. Identify Virtual Servers with SSL profiles
    Run 'tmsh list ltm virtual' to list all Virtual Servers. For each virtual server, examine whether it references a Client SSL or Server SSL profile in its configuration (look for 'client-ssl' or 'server-ssl' in the profiles list).
    Affected if Any Virtual Server is configured with a Client SSL or Server SSL profile on an affected version.
  3. Check for DNSSEC signing configuration
    Run 'tmsh list gtm dns' to view GTM/DNS settings, or check DNS profiles for DNSSEC signing enabled (look for 'dnssec' or 'sign' settings). Also check 'tmsh list net dns' for DNSSEC-related configuration.
    Affected if DNSSEC signing operations are enabled on the system.
  4. Verify exposed attack surface
    Review which Virtual Servers with SSL profiles are internet-facing or accessible from untrusted networks. Check the Virtual Server destination address and port configuration using 'tmsh list ltm virtual <name> destination'.
    Affected if Internet-facing Virtual Servers with SSL profiles exist on an affected version, or DNSSEC signing is performed on externally accessible systems.

A system is affected if it runs a vulnerable Big IP version (15.1.0-15.1.10, 16.1.0-16.1.5, or 17.1.0-17.1.1) AND has Virtual Servers configured with Client or Server SSL profiles, OR performs DNSSEC signing operations.

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 16.1.6 / 17.1.2 or later
Fixed in 16.1.617.1.2
Interim mitigation

Apply the vendor-supplied patch when available. In the interim, implement rate limiting, traffic filtering, or GeoIP blocking on affected Virtual Servers to mitigate abnormal traffic patterns.

Recommended fix High confidence

BIG-IP 16.1.6+ for 16.1.x; BIG-IP 17.1.2+ for 17.1.x; BIG-IP 15.1.11+ for 15.1.x (verify not EoTS)

  1. 1. Identify the currently installed Big IP version by running 'tmsh show sys version' or checking the web UI.
  2. 2. For version 15.1.x (15.1.0-15.1.10): Upgrade to BIG-IP 15.1.11 or later. Note: Verify 15.1.11 is not End of Technical Support (EoTS) before upgrading.
  3. 3. For version 16.1.x (16.1.0-16.1.5): Upgrade to BIG-IP 16.1.6 or later.
  4. 4. For version 17.1.x (17.1.0-17.1.1): Upgrade to BIG-IP 17.1.2 or later.
  5. 5. After upgrade, verify the fix by monitoring memory and CPU usage on virtual servers with SSL profiles and/or DNSSEC configurations.
  6. 6. Review release notes for any additional post-upgrade configuration requirements.
Caveat Upgrade may introduce behavior changes; test in non-production environment first; review release notes for deprecations

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

Fix this in Big Ip Access Policy Manager Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,860
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,176.

Scan for this in your stack

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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-2025-21087 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