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NVD / CVE Program· CNA f5

CVE-2021-23050: On BIG-IP Advanced WAF and BIG-IP ASM version 16.0.x before 16.0.1.2 and 15.1.x before 15.1.3 and NGINX App Protect on all versions before…

HighCVSS 7.5 · v3.1—No exploit No fix recorded

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: 0.46% (FIRST EPSS).
  • 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 Advanced WAF and BIG-IP ASM version 16.0.x before 16.0.1.2 and 15.1.x before 15.1.3 and NGINX App Protect on all versions before 3.5.0, when a cross-site request forgery (CSRF)-enabled policy is configured on a virtual server, an undisclosed HTML response may cause the bd process to terminate. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Published
Sep 14, 2021
Updated
Jun 16, 2026
EPSS
0.4% · 40th percentile

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 · 0.4%

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-2021-23050

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 advanced web application firewall
f5big-ip application security manager
f5nginx app protect

Affected versions

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

  • f5 big-ip advanced web application firewall15.1.0 and later · before 15.1.3.1
  • f5 big-ip advanced web application firewall16.0.0 and later · before 16.0.1.2
  • f5 big-ip application security manager15.1.0 and later · before 15.1.3.1
  • f5 big-ip application security manager16.0.0 and later · before 16.0.1.2
  • f5 nginx app protect1.0.0 and later · up to 1.3.0 inclusive
  • f5 nginx app protect2.0.0 and later · up to 2.3.0 inclusive
  • f5 nginx app protect3.0.0 and later · before 3.5.0

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 Advanced WAF and BIG-IP ASM; NGINX App Protect

    • BIG-IP Advanced WAF and BIG-IP ASM 16.0.x before 16.0.1.2 and 15.1.x before 15.1.3, NGINX App Protect all versions before 3.5.0affected

Same product

f5: all records

Other highest-scoring records for the same primary product.

  • CVE-2021-23031On version 16.0.x before 16.0.1.2, 15.1.x before 15.1.3, 14.1.x before 14.1.4.1, 13.1.x before 13.1.4, 12.1.x before 12.1.6, and 11.6.x…
    40Plan
  • CVE-2021-23029On version 16.0.x before 16.0.1.2, insufficient permission checks may allow authenticated users with guest privileges to perform…
    35Monitor
  • CVE-2021-23014On versions 16.0.x before 16.0.1.1, 15.1.x before 15.1.3, and 14.1.x before 14.1.4, BIG-IP Advanced WAF and ASM are missing authorization…
    35Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2021-22984Feb 12, 2021 · On BIG-IP Advanced WAF and ASM version 15.1.x before 15.1.0.2, 15.0.x before 15.0.1.4, 14.1.x before 14.1.2.5, 13.1.x before 13.1.3.4, 12.1.
    24Monitor
  • ← EarlierCVE-2021-22993Mar 31, 2021 · On BIG-IP Advanced WAF and BIG-IP ASM versions 16.0.x before 16.0.1.1, 15.1.x before 15.1.2, 14.1.x before 14.1.3.1, 13.1.x before…
    35Monitor
  • Later →CVE-2021-23053Sep 14, 2021 · On version 15.1.x before 15.1.3, 14.1.x before 14.1.3.1, and 13.1.x before 13.1.3.6, when the brute force protection feature of BIG-IP…
    21Monitor

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.

No history yet (it accumulates with the daily EPSS job).

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)

CWE-352 · Cross-Site Request Forgery (CSRF)

CVSS vector

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

nvd-primary

Root cause

State-changing requests rely on the session cookie the browser sends automatically; nothing verifies that the request came from the user’s own page.

The bug in code

The whole CWE-352 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

ts
app.use(session({ cookie: { httpOnly: true } }));app.post("/account/address", updateAddress);

Fixed

ts
app.use(session({ cookie: { httpOnly: true, sameSite: "lax" } }));app.post("/account/address", csrfProtection, updateAddress);

Attack context

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

ATT&CK techniques

—

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