dbcve.org
Big Ip Domain Name SystemApplication · F5

CVE-2023-41253

MEDIUM · 5.5 CVSS v3.1 Published 2023-10-10
Fix available
A fix is available. Upgrade to 15.1.9 / 16.1.4 or later.
See remediation →
57/100
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
When on BIG-IP DNS or BIG-IP LTM enabled with DNS Services License, and a TSIG key is created, it is logged in plaintext in the audit log.  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

When a TSIG (Transaction Signature) key is created on affected BIG-IP DNS or BIG-IP LTM systems with the DNS Services License, the plaintext key value is written to the audit log instead of being masked or hashed. This exposes the cryptographic key to anyone with audit log access, potentially allowing attackers to obtain the TSIG key and perform DNS spoofing or man-in-the-middle attacks on DNS communications.

MitigationUpgrade to a patched version of BIG-IP DNS/LTM that masks TSIG keys in audit logs. Alternatively, avoid creating new TSIG keys until the patch is applied and audit existing logs for any plaintext TSIG key exposure.

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 Domain Name SystemApplication
Affected:>= 13.1.0, <= 14.1.5>= 15.1.0, < 15.1.9>= 16.1.0, < 16.1.4
Big Ip Local Traffic ManagerApplication
Affected:>= 13.1.0, <= 14.1.5>= 15.1.0, < 15.1.9>= 16.1.0, < 16.1.4

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

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/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. Check BIG-IP version
    Run `tmsh show /sys version` or check System > Software Management > ISO Image in the GUI
    Affected if Version is >= 13.1.0 and <= 14.1.5, or >= 15.1.0 and < 15.1.9, or >= 16.1.0 and < 16.1.4
  2. Confirm DNS Services license on LTM
    Run `tmsh show /sys license` and look for 'DNS Services' in the licensed modules, or check in the GUI under System > License
    Affected if LTM system has the DNS Services License provisioned (BIG-IP DNS is always affected if version is vulnerable)
  3. Identify existing TSIG keys
    Run `tmsh list /ltm dns tsig key all-properties` or check the GUI under DNS > Keys > TSIG Keys
    Affected if Any TSIG keys exist on the system (the vulnerability triggers when a TSIG key is created)
  4. Search audit logs for plaintext TSIG keys
    Run `tmsh show /audit` or review logs in the GUI under System > Logs > Audit. Search for log entries containing TSIG key names and inspect whether the key value appears in plaintext (unmasked)
    Affected if Audit logs contain plaintext TSIG key values (indicates active exploitation or exposure)

The environment is affected if the BIG-IP version is within the vulnerable ranges AND DNS Services is licensed AND TSIG keys exist, especially if audit logs reveal unmasked plaintext TSIG key values.

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 15.1.9 / 16.1.4 or later
Fixed in 15.1.916.1.4
Interim mitigation

Upgrade to a patched version of BIG-IP DNS/LTM that masks TSIG keys in audit logs. Alternatively, avoid creating new TSIG keys until the patch is applied and audit existing logs for any plaintext TSIG key exposure.

Recommended fix High confidence

15.1.9 or 16.1.4 (depending on your branch)

  1. 1. Identify the currently installed BIG-IP version (DNS or LTM) using 'tmsh show sys version'
  2. 2. If running 13.x or 14.x versions: Plan migration to a supported version (15.1.x or 16.1.x) as these older branches have reached End of Technical Support
  3. 3. If running 15.1.0-15.1.8: Upgrade to version 15.1.9 or later
  4. 4. If running 16.1.0-16.1.3: Upgrade to version 16.1.4 or later
  5. 5. After upgrade, verify that TSIG keys are no longer logged in plaintext by reviewing /var/log/audit for any TSIG key entries
  6. 6. Alternatively, if upgrade is not immediately feasible, review log retention policies to limit exposure of audit logs containing TSIG keys
Caveat Verify compatibility with your current configuration and ensure 15.1.x/16.1.x are within your supported maintenance window; 13.x and 14.x branches are EoTS and require migration to newer versions

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

Fix this in Big Ip Domain Name System Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,600
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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-2023-41253 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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