Skip to content
Noroxi
CVE-2021-23027· NVD / CVE Program· CNA f5

On version 16.0.x before 16.0.1.2, 15.1.x before 15.1.3.1, and 14.1.x before 14.1.4.3, a DOM based cross-site scripting (XSS) vulnerability

Noroxi assessment

Priority: Monitor (action score 24/100)

  • 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: 0.58% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. A user must open a link or visit a page. No special conditions are required; it is repeatable.
  • According to the record, no fixed version is available yet.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

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 version 16.0.x before 16.0.1.2, 15.1.x before 15.1.3.1, and 14.1.x before 14.1.4.3, a DOM based cross-site scripting (XSS) vulnerability exists in an undisclosed page of the BIG-IP Configuration utility that allows an attacker to execute JavaScript in the context of the currently logged-in user. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

MediumCVSS 6.1 · v3.1—No exploit No fix recorded
Published
Sep 14, 2021
Updated
Jun 16, 2026
EPSS
0.5% · 46th percentile

Report tools

JSON

Action score

24

Monitor

Low priority for now.

CVSS
24 / 40 · 6.1 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.5%

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-2021-23027

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

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits instantly.

Your free account also gets you

Running WordPress? Scan your site free with WP Lens

  • Stack alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
All free tools

Sign up with email · Have an account? Sign in

Free account, no card. Unfollow any time.

Running WordPress? Scan your site free with WP Lens

Is your version affected? Check it

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.

We use this product, ask for help

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 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

Limit the impact of XSS

This is a cross-site scripting (XSS) vulnerability. A well-configured Content-Security-Policy doesn't fix it, but greatly reduces its impact. Check your site's CSP and other security headers for free.

Check security headers

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 manager14.1.0 and later · up to 14.1.4 inclusive
  • f5 big-ip access policy manager15.1.0 and later · up to 15.1.3 inclusive
  • f5 big-ip access policy manager16.0.0 and later · up to 16.0.1.1 inclusive
  • f5 big-ip advanced firewall manager14.1.0 and later · up to 14.1.4 inclusive
  • f5 big-ip advanced firewall manager15.1.0 and later · up to 15.1.3 inclusive
  • f5 big-ip advanced firewall manager16.0.0 and later · up to 16.0.1.1 inclusive
  • f5 big-ip advanced web application firewall14.1.0 and later · up to 14.1.4 inclusive
  • f5 big-ip advanced web application firewall15.1.0 and later · up to 15.1.3 inclusive
  • f5 big-ip advanced web application firewall16.0.0 and later · up to 16.0.1.1 inclusive
  • f5 big-ip analytics14.1.0 and later · up to 14.1.4 inclusive
  • f5 big-ip analytics15.1.0 and later · up to 15.1.3 inclusive
  • f5 big-ip analytics16.0.0 and later · up to 16.0.1.1 inclusive
  • f5 big-ip application acceleration manager14.1.0 and later · up to 14.1.4 inclusive
  • f5 big-ip application acceleration manager15.1.0 and later · up to 15.1.3 inclusive
  • f5 big-ip application acceleration manager16.0.0 and later · up to 16.0.1.1 inclusive
  • f5 big-ip application security manager14.1.0 and later · up to 14.1.4 inclusive
  • f5 big-ip application security manager15.1.0 and later · up to 15.1.3 inclusive
  • f5 big-ip application security manager16.0.0 and later · up to 16.0.1.1 inclusive
  • f5 big-ip ddos hybrid defender14.1.0 and later · up to 14.1.4 inclusive
  • f5 big-ip ddos hybrid defender15.1.0 and later · up to 15.1.3 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

    • 16.0.x before 16.0.1.2, 15.1.x before 15.1.3.1, and 14.1.x before 14.1.4.3affected

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-2021-23025Sep 14, 2021 · On version 15.1.x before 15.1.0.5, 14.1.x before 14.1.3.1, 13.1.x before 13.1.3.5, and all versions of 12.1.x and 11.6.x, an authenticated r
    36Monitor
  • ← EarlierCVE-2021-23026Sep 14, 2021 · BIG-IP version 16.0.x before 16.0.1.2, 15.1.x before 15.1.3, 14.1.x before 14.1.4.2, 13.1.x before 13.1.4.1, and all versions of 12.1.x and
    35Monitor
  • Later →CVE-2021-23054Sep 27, 2021 · On version 16.x before 16.1.0, 15.1.x before 15.1.4, 14.1.x before 14.1.4.4, and all versions of 13.1.x, 12.1.x, and 11.6.x, a reflected cro
    24Monitor

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.

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).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • A user must open a link or visit a page.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
low · data can be read
Integrity
low · data or configuration can be modified
Availability
none

Impact can extend beyond the vulnerable component (scope changes).

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Changed
Confidentiality impact
Low
Integrity impact
Low
Availability impact
None

CVSS vector

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

nvd-primary

Root cause

User content is inserted into the page as HTML. The browser interprets the content as code rather than data.

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

Vulnerable

ts
commentEl.innerHTML = comment.body;

Fixed

ts
commentEl.textContent = comment.body;

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