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Big Ip Policy Enforcement ManagerApplication · F5

CVE-2025-35995

HIGH · 7.5 CVSS v3.1 Published 2025-05-07
Fix available
A fix is available. Upgrade to 15.1.10.7.0.4.5 / 16.1.6 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 a BIG-IP PEM system is licensed with URL categorization, and the URL categorization policy or an iRule with the urlcat command is enabled on a virtual server, undisclosed requests can cause the Traffic Management Microkernel (TMM) to terminate. 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 BIG-IP PEM systems allows undisclosed requests to crash the Traffic Management Microkernel (TMM) when URL categorization policies or iRules using the urlcat command are enabled on a virtual server. The vulnerability is triggered by specifically crafted requests that cause TMM to terminate, disrupting all traffic processing for affected virtual servers.

MitigationApply the F5 vendor patch when available. Until then, consider disabling URL categorization policies or urlcat iRules on affected virtual servers if operationally feasible, or implement additional upstream DDoS/DOS protections.

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 Policy Enforcement ManagerApplication
Affected:>= 15.1.0, < 15.1.10.7.0.4.5>= 16.1.0, < 16.1.6>= 17.1.0, < 17.1.2.2

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 BIG-IP PEM version
    Run 'tmsh show /sys version' or check the version through the web UI under System > Software Management > Volume Name. Compare the installed version against the affected ranges: 15.1.0 to 15.1.10.7.0.4.5, 16.1.0 to 16.1.6, or 17.1.0 to 17.1.2.
    Affected if The installed version falls within any of the affected version ranges.
  2. List virtual servers with PEM URL categorization policies
    Run 'tmsh list /pem policy' to enumerate all PEM policies. For each policy, inspect whether URL categorization rules are defined. Cross-reference with virtual servers assigned these policies using 'tmsh list /ltm virtual <name>' for each virtual server.
    Affected if Any virtual server has a PEM policy with URL categorization rules enabled.
  3. Search for iRules using the urlcat command
    Run 'tmsh list /ltm rule all' to list all iRules. Search the output for any iRule containing 'urlcat' as this command is used for URL categorization. Identify which virtual servers have these iRules assigned via their profiles.
    Affected if Any virtual server has an iRule that invokes the urlcat command.
  4. Confirm attack surface exposure
    Cross-reference the virtual servers identified in steps 2 and 3 with the affected version identified in step 1. Determine if TMM is actively processing traffic on these virtual servers using 'tmsh show /ltm virtual' or similar commands.
    Affected if The BIG-IP runs an affected version AND has virtual servers with either URL categorization policies or urlcat iRules enabled.

You are affected if your BIG-IP PEM runs an affected version (15.1.x before 15.1.10.7.0.4.5, 16.1.x before 16.1.6, or 17.1.x before 17.1.2) AND has any virtual server with URL categorization policies or iRules using the urlcat command enabled.

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 15.1.10.7.0.4.5 / 16.1.6 / 17.1.2.2 or later
Fixed in 15.1.10.7.0.4.516.1.617.1.2.2
Interim mitigation

Apply the F5 vendor patch when available. Until then, consider disabling URL categorization policies or urlcat iRules on affected virtual servers if operationally feasible, or implement additional upstream DDoS/DOS protections.

Recommended fix High confidence

15.1.0-15.1.10.x -> 15.1.10.7.0.4.5 or later; 16.1.0-16.1.x -> 16.1.6 or later; 17.1.0-17.1.x -> 17.1.2.2 or later

  1. 1. Identify the current BIG-IP PEM version by running 'tmsh show sys version' or checking the GUI at System > Software > IMAGE/DETAILS
  2. 2. Confirm URL categorization policy or iRules with 'urlcat' command are in use on virtual servers
  3. 3. Schedule a maintenance window as the upgrade may require brief service interruption
  4. 4. Create a UCS backup before upgrading: 'tmsh save sys ucs <backup-name>'
  5. 5. Download the appropriate hotfix from F5 Downloads (my.f5.com) for your version branch
  6. 6. Install the hotfix via GUI (System > Software > Upload) or CLI: 'tmsh install sys software hotfix <hotfix-file> volume <volume>'
  7. 7. After installation, verify the fix is applied by checking the version matches or exceeds the fixed release for your branch
  8. 8. Test that TMM remains stable and URL categorization functions correctly
Caveat Hotfix installations on BIG-IP may require reboot; verify compatibility with other installed modules and review F5 release notes for any known issues

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

Fix this in Big Ip Policy Enforcement Manager Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing12.0 h
  • Review / QA4.0 h
28.0 hours of engineering $4,760
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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-2025-35995 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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