CVE-2021-22979Network attack vector

Reflected XSS via undisclosed Configuration utility page

Published Feb 12, 2021 · Updated Aug 3, 2024

Reflected XSS in F5 Networks BIG-IP allows remote attackers to execute JavaScript in a logged-in Configuration utility user's session. The affected page and the input reflected without neutralization are undisclosed in F5's public record. Exploitation requires Fraud Protection Service to be provisioned and a logged-in user to interact with attacker-controlled input; script execution is bounded to that user's browser context.

CVSS severity6.1
Medium
EPSS probability0.60%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reflected XSS in F5 Networks BIG-IP allows remote attackers to execute JavaScript in a logged-in Configuration utility user's session. The affected page and the input reflected without neutralization are undisclosed in F5's public record. Exploitation requires Fraud Protection Service to be provisioned and a logged-in user to interact with attacker-controlled input; script execution is bounded to that user's browser context.

The record

CVE
CVE-2021-22979
Published
Feb 12, 2021
Updated
Aug 3, 2024
Vendor
F5 Networks
Product
BIG-IP
Classifications
CWE-79
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 12, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=16.0.x before 16.0.1, 15.1.x before 15.1.1, 14.1.x before 14.1.2.8, 13.1.x before 13.1.3.5, and all 12.1.x versions

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

F5 Networks · BIG-IPversion=16.0.x before 16.0.1, 15.1.x before 15.1.1, 14.1.x before 14.1.2.8, 13.1.x before 13.1.3.5, and all 12.1.x versions

Published CVSS scores

6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:P/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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