Skip to content
Noroxi
CVE-2021-22981· NVD / CVE Program· CNA f5

On all versions of BIG-IP 12.1.x and 11.6.x, the original TLS protocol includes a weakness in the master secret negotiation that is mitigate

On all versions of BIG-IP 12.1.x and 11.6.x, the original TLS protocol includes a weakness in the master secret negotiation that is mitigated by the Extended Master Secret (EMS) extension defined in RFC 7627. TLS connections that do not use EMS are vulnerable to man-in-the-middle attacks during renegotiation. Note: Software versions which have reached End of Software Development (EoSD) are not evaluated.

MediumCVSS 4.8 · v3.1—No exploit No fix recorded
Published
Feb 12, 2021
Updated
Jun 16, 2026
EPSS
0.6% · 44th percentile
CWE
—
Follow this CVE

Sign in to follow · You’ll be notified if a followed record enters KEV, gets an exploit or is updated.

Report tools

JSON

Action score

19

Monitor

Low priority for now.

CVSS
19 / 40 · 4.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.6%

Affected systems

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

and 2 more

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 manager11.6.1 and later · up to 11.6.5 inclusive
  • f5 big-ip access policy manager12.1.0 and later · up to 12.1.5 inclusive
  • f5 big-ip advanced firewall manager11.6.1 and later · up to 11.6.5 inclusive
  • f5 big-ip advanced firewall manager12.1.0 and later · up to 12.1.5 inclusive
  • f5 big-ip advanced web application firewall11.6.1 and later · up to 11.6.5 inclusive
  • f5 big-ip advanced web application firewall12.1.0 and later · up to 12.1.5 inclusive
  • f5 big-ip analytics11.6.1 and later · up to 11.6.5 inclusive
  • f5 big-ip analytics12.1.0 and later · up to 12.1.5 inclusive
  • f5 big-ip application acceleration manager11.6.1 and later · up to 11.6.5 inclusive
  • f5 big-ip application acceleration manager12.1.0 and later · up to 12.1.5 inclusive
  • f5 big-ip application security manager11.6.1 and later · up to 11.6.5 inclusive
  • f5 big-ip application security manager12.1.0 and later · up to 12.1.5 inclusive
  • f5 big-ip ddos hybrid defender11.6.1 and later · up to 11.6.5 inclusive
  • f5 big-ip ddos hybrid defender12.1.0 and later · up to 12.1.5 inclusive
  • f5 big-ip domain name system11.6.1 and later · up to 11.6.5 inclusive
  • f5 big-ip domain name system12.1.0 and later · up to 12.1.5 inclusive
  • f5 big-ip fraud protection service11.6.1 and later · up to 11.6.5 inclusive
  • f5 big-ip fraud protection service12.1.0 and later · up to 12.1.5 inclusive
  • f5 big-ip global traffic manager11.6.1 and later · up to 11.6.5 inclusive
  • f5 big-ip global traffic manager12.1.0 and later · up to 12.1.5 inclusive

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

    • All versions of 12.1.x and 11.6.xaffected

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
  • CVE-2023-46747BIG-IP Configuration utility unauthenticated remote code execution vulnerabilityKEV
    98Now
  • CVE-2021-22991On 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
    87Now
  • CVE-2026-94127BIG-IP APM OAuth vulnerabilityKEV
    68This week

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.
  • Special conditions such as timing or configuration are required.

If successful

Confidentiality
low · data can be read
Integrity
low · data or configuration can be modified
Availability
none
Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
Low
Integrity impact
Low
Availability impact
None

Weakness class (CWE)

—

CVSS vector

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

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.

Noroxi analysis

No Noroxi analysis for this record yet

We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.

We use this product, ask for help

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