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CVE-2020-5941· NVD / CVE Program· CNA f5

On BIG-IP versions 16.0.0-16.0.0.1 and 15.1.0-15.1.0.5, using the RESOLV::lookup command within an iRule may cause the Traffic Management Mi

Noroxi assessment

Priority: Monitor (action score 30/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 1% (FIRST EPSS); higher than 63.8% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to the record, no fixed version is available yet.

Low priority for now. Update when a fix is released; follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

On BIG-IP versions 16.0.0-16.0.0.1 and 15.1.0-15.1.0.5, using the RESOLV::lookup command within an iRule may cause the Traffic Management Microkernel (TMM) to generate a core file and restart. This issue occurs when data exceeding the maximum limit of a hostname passes to the RESOLV::lookup command.

HighCVSS 7.5 · v3.1—No exploit No fix recorded
Published
Nov 5, 2020
Updated
Jun 16, 2026
EPSS
1.0% · 63th percentile
CWE
—

Report tools

JSON

Action score

30

Monitor

Low priority for now.

CVSS
30 / 40 · 7.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 1.0%

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2020-5941

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
f5big-ip access policy manager
f5big-ip advanced firewall manager
f5big-ip analytics
f5big-ip application acceleration manager
f5big-ip application security manager
f5big-ip domain name system
f5big-ip fraud protection service
f5big-ip global traffic manager
f5big-ip link controller
f5big-ip local traffic manager
f5big-ip policy enforcement manager

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • f5 big-ip access policy manager15.1.0 and later · before 15.1.1
  • f5 big-ip access policy manager16.0.0 and later · before 16.0.1
  • f5 big-ip advanced firewall manager15.1.0 and later · before 15.1.1
  • f5 big-ip advanced firewall manager16.0.0 and later · before 16.0.1
  • f5 big-ip analytics15.1.0 and later · before 15.1.1
  • f5 big-ip analytics16.0.0 and later · before 16.0.1
  • f5 big-ip application acceleration manager15.1.0 and later · before 15.1.1
  • f5 big-ip application acceleration manager16.0.0 and later · before 16.0.1
  • f5 big-ip application security manager15.1.0 and later · before 15.1.1
  • f5 big-ip application security manager16.0.0 and later · before 16.0.1
  • f5 big-ip domain name system15.1.0 and later · before 15.1.1
  • f5 big-ip domain name system16.0.0 and later · before 16.0.1
  • f5 big-ip fraud protection service15.1.0 and later · before 15.1.1
  • f5 big-ip fraud protection service16.0.0 and later · before 16.0.1
  • f5 big-ip global traffic manager15.1.0 and later · before 15.1.1
  • f5 big-ip global traffic manager16.0.0 and later · before 16.0.1
  • f5 big-ip link controller15.1.0 and later · before 15.1.1
  • f5 big-ip link controller16.0.0 and later · before 16.0.1
  • f5 big-ip local traffic manager15.1.0 and later · before 15.1.1
  • f5 big-ip local traffic manager16.0.0 and later · before 16.0.1

Versions reported by the vendor

Affected version ranges reported by the assigning authority (f5). Independent of NVD's CPE analysis and usually ahead of it.

  • n/a BIG-IP

    • 16.0.0-16.0.0.1, 15.1.0-15.1.0.5affected

Same product

f5: all records

Other highest-scoring records for the same primary product.

  • CVE-2022-1388On F5 BIG-IP 16.1.x versions prior to 16.1.2.2, 15.1.x versions prior to 15.1.5.1, 14.1.x versions prior to 14.1.4.6, 13.1.x versions prior KEV
    99Now
  • CVE-2021-22986On BIG-IP versions 16.0.x before 16.0.1.1, 15.1.x before 15.1.2.1, 14.1.x before 14.1.4, 13.1.x before 13.1.3.6, and 12.1.x before 12.1.5.3 KEV
    99Now
  • CVE-2020-5902In BIG-IP versions 15.0.0-15.1.0.3, 14.1.0-14.1.2.5, 13.1.0-13.1.3.3, 12.1.0-12.1.5.1, and 11.6.1-11.6.5.1, the Traffic Management User InteKEV
    99Now

Published before and after this one in the same product

  • ← EarlierCVE-2020-5939Nov 5, 2020 · In versions 16.0.0-16.0.0.1, 15.1.0-15.1.0.3, 15.0.0-15.0.1.3, 14.1.0-14.1.2.6, and 13.1.0-13.1.3.4, BIG-IP Virtual Edition (VE) systems on
    30Monitor
  • ← EarlierCVE-2020-5940Nov 5, 2020 · In versions 16.0.0-16.0.0.1, 15.1.0-15.1.0.5, and 14.1.0-14.1.2.3, a stored cross-site scripting (XSS) vulnerability exists in an undisclose
    21Monitor
  • Later →CVE-2020-5943Nov 5, 2020 · In versions 14.1.0-14.1.0.1 and 14.1.2.5-14.1.2.7, when a BIG-IP object is created or listed through the REST interface, the protected field
    26Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

—

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records