CVE-2021-24436

MEDIUMNVD 6.16.1—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.1 under NVD CVSS v3. EPSS exploit probability: 1.9% (78th percentile of EPSS-scored CVEs). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
Elevated
6.1EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 1.9%CVSS: 6.1Exploit: Elevated riskExposed services: Not assessed

No fix is confirmed yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for the fix.

The W3 Total Cache WordPress plugin before 2.1.4 was vulnerable to a reflected Cross-Site Scripting (XSS) security vulnerability within the "extension" parameter in the Extensions dashboard, which is output in an attribute without being escaped first. This could allow an attacker, who can convince an authenticated admin into clicking a link, to run malicious JavaScript within the user's web browser, which could lead to full site compromise.

CVSS v3
6.1
EG Score
6.1MEDIUMmedium confidence
EG Risk
48
EG Risk 48/100CISA SSVC

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity61% × 45%
Exploitation40% × 40%
Automatability30% × 15%
CISA SSVC: Track at low or medium mission impact; Track* or Attend at high (mission-essential systems).
Action: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.
EPSS PROB
1.9%
EPSS %ILE
79th
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Track* or Attend at high (mission-essential systems).

No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.

Exploitation public PoC (EG-KEV: elevated) · Automatable unknown (not published for this CVE) · Technical impact partial (CVSS below 9.0). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

July 19, 2021

Last Modified

November 21, 2024

References (2)

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 8× in last 7d / 31× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 172 total refreshes for this CVE.

  1. 2026-10-05 17:40 UTCEPSS rescore
  2. 2026-10-04 23:18 UTCEPSS rescore
  3. 2026-10-03 14:22 UTCEPSS rescore
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  6. 2026-10-01 19:46 UTCEPSS rescore
  7. 2026-09-30 15:31 UTCEG score recompute
  8. 2026-09-30 15:00 UTCEPSS rescore
  9. 2026-09-28 13:47 UTCEPSS rescore
  10. 2026-09-27 13:41 UTCEPSS rescore
  11. 2026-09-26 15:54 UTCEPSS rescore
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  24. 2026-09-15 03:06 UTCEPSS rescore
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  1. 2026-09-11 09:33 UTCEPSS rescore
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  3. 2026-09-08 21:56 UTCEPSS rescore
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  5. 2026-09-06 13:44 UTCEPSS rescore
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  7. 2026-09-05 15:25 UTCEPSS rescore
  8. 2026-09-04 13:57 UTCEPSS rescore
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  13. 2026-08-30 19:14 UTCEPSS rescore
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  15. 2026-08-28 21:37 UTCEPSS rescore
  16. 2026-08-27 14:22 UTCEPSS rescore
  17. 2026-08-26 14:42 UTCEPSS rescore
  18. 2026-08-25 13:45 UTCEPSS rescore
  19. 2026-08-23 00:16 UTCEPSS rescore
  20. 2026-08-21 23:46 UTCEPSS rescore
  21. 2026-08-20 22:52 UTCEPSS rescore
  22. 2026-08-19 17:01 UTCEPSS rescore
  23. 2026-08-18 13:45 UTCEPSS rescore
  24. 2026-08-17 13:43 UTCEPSS rescore
  25. 2026-08-16 14:52 UTCEPSS rescore
  26. 2026-08-16 02:11 UTCEPSS rescore
  27. 2026-08-15 01:27 UTCEPSS rescore
  28. 2026-08-13 21:57 UTCEPSS rescore
  29. 2026-08-12 13:47 UTCEPSS rescore
  30. 2026-08-11 13:38 UTCEPSS rescore
  31. 2026-08-09 13:43 UTCEPSS rescore
  32. 2026-08-08 16:33 UTCEPSS rescore
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  41. 2026-07-30 16:25 UTCEPSS rescore
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  44. 2026-07-26 14:52 UTCEPSS rescore
  45. 2026-07-25 14:15 UTCEPSS rescore
  46. 2026-07-24 14:15 UTCEPSS rescore
  47. 2026-07-23 14:15 UTCEPSS rescore
  48. 2026-07-23 01:58 UTCEG score recompute
  49. 2026-07-22 22:44 UTCEG score recompute
  50. 2026-07-22 14:05 UTCEPSS rescore
  51. 2026-07-21 15:22 UTCEPSS rescore
  52. 2026-07-21 15:22 UTCEPSS rescore
  53. 2026-07-20 17:04 UTCEPSS rescore
  54. 2026-07-19 14:28 UTCEPSS rescore
  55. 2026-07-19 02:26 UTCEPSS rescore
  56. 2026-07-18 10:02 UTCEPSS rescore
  57. 2026-07-16 17:00 UTCEPSS rescore
  58. 2026-07-15 16:55 UTCEPSS rescore
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  60. 2026-07-15 01:57 UTCEPSS rescore
  61. 2026-07-13 22:27 UTCEPSS rescore
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  63. 2026-07-13 06:10 UTCEPSS rescore
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  65. 2026-07-12 05:44 UTCEPSS rescore
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  67. 2026-07-11 08:25 UTCEPSS rescore
  68. 2026-07-09 19:07 UTCEPSS rescore
  69. 2026-07-08 15:12 UTCEPSS rescore
  70. 2026-07-07 13:43 UTCEPSS rescore
  71. 2026-07-06 16:25 UTCEPSS rescore
  72. 2026-07-06 02:21 UTCEPSS rescore
  73. 2026-07-06 02:21 UTCEPSS rescore
  74. 2026-07-05 02:28 UTCEPSS rescore
  75. 2026-07-05 02:28 UTCEPSS rescore

Publicly available exploits

(1 reference)

Working exploit code is in the public domain. Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • Nucleihttp/cves/2021/CVE-2021-24436.yaml
    First seen Jan 1, 2021

    WordPress W3 Total Cache <2.1.4 - Cross-Site Scripting

    Open source ↗

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2021-24436?
CVE-2021-24436 is a medium vulnerability published on July 19, 2021. The W3 Total Cache WordPress plugin before 2.1.4 was vulnerable to a reflected Cross-Site Scripting (XSS) security vulnerability within the "extension" parameter in the Extensions dashboard, which is output in an attribute without being escaped first. This could allow an attacker, who can convince…
When was CVE-2021-24436 disclosed?
CVE-2021-24436 was first published on July 19, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-24436 actively exploited?
CVE-2021-24436 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1.9% probability of exploitation in the next 30 days (79th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2021-24436?
CVE-2021-24436 has a CVSS v3 base score of 6.1 (NVD).
How do I remediate CVE-2021-24436?
No fix for CVE-2021-24436 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix.

Dependency Blast Radius

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