CVE-2020-28871

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2022-05-24. NVD baseline CVSS 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 3 sources updated this weekWeaponized
9.8
EchelonGraph verdictPatch this weekExploitation is likely or a public exploit exists.
  • High exploitation likelihood — EPSS 86%
CISA-KEV: Not listedEPSS: 86%CVSS: 9.8Exploit: NoneExposed: 0

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

Remote code execution in Monitorr v1.7.6m in upload.php allows an unauthorized person to execute arbitrary code on the server-side via an insecure file upload.

CVSS v3
9.8
EG Score
9.8(medium)
EG Risk
83(Track*)
EG Risk 83/100SSVC: Track*

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
Severity98% × 45%
Exploitation86% × 40%
Automatability30% × 15%
Action: Watch closely — could escalate to Attend.
EPSS
99.7%
KEV
Not listed

Published

February 10, 2021

Last Modified

November 21, 2024

Advisory Details (1)

Auto-updated Jul 9, 2026
🔬 Proof of concept available. No patch confirmed yet.
generic🟡 PoC Available

Monitorr 1.7.6m - Remote Code Execution (Unauthenticated) - PHP webapps Exploit

https://www.exploit-db.com/exploits/48980

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 8× in last 7d / 17× 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.

  1. 2026-07-23 01:52 UTCEG score recompute
  2. 2026-07-22 22:38 UTCEG score recompute
  3. 2026-07-22 14:05 UTCEPSS rescore
  4. 2026-07-21 15:22 UTCEPSS rescore
  5. 2026-07-21 15:22 UTCEPSS rescore
  6. 2026-07-20 17:04 UTCEPSS rescore
  7. 2026-07-20 17:04 UTCEPSS rescore
  8. 2026-07-19 02:22 UTCOSV refresh
  9. 2026-07-15 16:55 UTCEPSS rescore
  10. 2026-07-15 16:55 UTCEPSS rescore
  11. 2026-07-12 05:44 UTCEPSS rescore
  12. 2026-07-09 19:07 UTCEPSS rescore
  13. 2026-07-01 09:18 UTCOSV refresh
  14. 2026-06-28 04:54 UTCEPSS rescore
  15. 2026-06-28 04:54 UTCEPSS rescore
  16. 2026-06-24 14:03 UTCEPSS rescore
  17. 2026-06-24 14:03 UTCEPSS rescore
  18. 2026-06-23 21:31 UTCEPSS rescore
  19. 2026-06-23 21:31 UTCEPSS rescore
  20. 2026-06-15 17:46 UTCEPSS rescore
  21. 2026-06-13 22:58 UTCEPSS rescore
  22. 2026-06-13 14:43 UTCOSV refresh
  23. 2026-06-06 13:46 UTCEPSS rescore
  24. 2026-06-06 13:45 UTCEPSS rescore
  25. 2026-06-05 22:45 UTCEPSS rescore
Show 10 more
  1. 2026-06-05 22:45 UTCEPSS rescore
  2. 2026-06-01 13:50 UTCEPSS rescore
  3. 2026-05-29 13:42 UTCEPSS rescore
  4. 2026-05-27 13:39 UTCEPSS rescore
  5. 2026-05-27 13:39 UTCEPSS rescore
  6. 2026-05-26 21:02 UTCEG score recompute
  7. 2026-05-26 21:02 UTCGHSA enrichment
  8. 2026-05-26 13:42 UTCEPSS rescore
  9. 2026-05-26 13:42 UTCEPSS rescore
  10. 2026-05-23 14:41 UTCOSV refresh

Publicly available exploits

(2 references)

Working exploit code is in the public domain (1 Metasploit module). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • Metasploitexploit/multi/http/monitorr_webshell_rce_cve_2020_28871✓ verified
    First seen Nov 16, 2020

    Monitorr unauthenticated Remote Code Execution (RCE)

    Open source ↗
  • Nucleihttp/cves/2020/CVE-2020-28871.yaml
    First seen Jan 1, 2020

    Monitorr 1.7.6m - Unauthenticated Remote Code Execution

    Open source ↗

Frequently asked(5)

What is CVE-2020-28871?
CVE-2020-28871 is a critical vulnerability published on February 10, 2021. Remote code execution in Monitorr v1.7.6m in upload.php allows an unauthorized person to execute arbitrary code on the server-side via an insecure file upload.
When was CVE-2020-28871 disclosed?
CVE-2020-28871 was first published in the National Vulnerability Database on February 10, 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-2020-28871 actively exploited?
CVE-2020-28871 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 99.7% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2020-28871?
CVE-2020-28871 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2020-28871?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2020-28871, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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