CVE-2021-24870Network attack vector

Stored XSS via forged CDN settings request

Published Jan 16, 2024 · Updated Jan 9, 2026

Stored XSS in WP Fastest Cache before 0.9.5 allows remote attackers to execute script via a forged administrator CDN-settings request. CdnWPFC::save_cdn_integration checks user capability but omits nonce validation and stores unsanitized CDN option values. An administrator must be logged in and induced to submit the request; the stored script can perform actions available to that administrator.

CVSS severity6.1
Medium
EPSS probability0.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Stored XSS in WP Fastest Cache before 0.9.5 allows remote attackers to execute script via a forged administrator CDN-settings request. CdnWPFC::save_cdn_integration checks user capability but omits nonce validation and stores unsanitized CDN option values. An administrator must be logged in and induced to submit the request; the stored script can perform actions available to that administrator.

The record

CVE
CVE-2021-24870
Published
Jan 16, 2024
Updated
Jan 9, 2026
Vendor
Emre Vona
Product
WP Fastest Cache
Classifications
CWE-79, CWE-352, T1189
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 16, 2024CVE publishedPublication date reported by the CVE source.
  2. Jan 9, 2026Record 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=0 <0.9.5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Emre Vona · WP Fastest Cacheversion=0 <0.9.5

Published CVSS scores

6.1NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
6.1CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
8.8WordfenceCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 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')
CWE-352Cross-Site Request Forgery (CSRF)
T1189Drive-by Compromise

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo