CVE-2020-28871

CRITICAL IN THE WILD NUCLEI

Monitorr 1.7.6m - Unauthenticated Remote Code Execution via Insecure File Upload

Title source: llm
STIX 2.1

Exploitation Summary

CVE-2020-28871 has been observed exploited in the wild (reported by InTheWild.io). EIP tracks 2 public exploits from researchers including Lyhin\'s Lab, including a Metasploit module exploits/multi/http/monitorr_webshell_rce_cve_2020_28871. A Nuclei detection template is also available.

AI-analyzed exploit summary This exploit targets Monitorr 1.7.6m by uploading a malicious PHP file via an unauthenticated file upload vulnerability, then triggering it to execute a reverse shell. The payload uses a GIF magic number to bypass basic file type checks.

Description

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.

Exploits (2)

exploitdb WORKING POC VERIFIED
by Lyhin\'s Lab · pythonwebappsphp
https://www.exploit-db.com/exploits/48980

This exploit targets Monitorr 1.7.6m by uploading a malicious PHP file via an unauthenticated file upload vulnerability, then triggering it to execute a reverse shell. The payload uses a GIF magic number to bypass basic file type checks.

Classification
Working Poc 95%
Attack Type
Rce
Complexity
Trivial
Reliability
Reliable
Target: Monitorr 1.7.6m
No auth needed
Prerequisites: Network access to the target · Target running Monitorr 1.7.6m
devstral-2 · analyzed Feb 16, 2026 Full analysis →
metasploit WORKING POC EXCELLENT
rubypocphp
https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/multi/http/monitorr_webshell_rce_cve_2020_28871.rb

This Metasploit module exploits an arbitrary file upload vulnerability in Monitorr (CVE-2020-28871) to achieve unauthenticated remote code execution. It uploads a malicious PHP webshell disguised as a GIF file and executes commands via HTTP requests.

Classification
Working Poc 100%
Attack Type
Rce
Complexity
Moderate
Reliability
Reliable
Target: Monitorr versions 1.7.6m, 1.7.7d and below
No auth needed
Prerequisites: Network access to the target web server · Monitorr application running with vulnerable version
devstral-2 · analyzed Feb 16, 2026 Full analysis →

Nuclei Templates (1)

Monitorr 1.7.6m - Unauthenticated Remote Code Execution
CRITICALby gy741
Shodan: http.favicon.hash:"-211006074"
FOFA: icon_hash="-211006074"

Scores

CVSS v3 9.8
EPSS 0.9392
EPSS Percentile 99.9%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Details

InTheWild.io 2021-04-18
CWE
CWE-434
Status published
Products (1)
monitorr/monitorr 1.7.6m
Published Feb 10, 2021
Tracked Since Feb 18, 2026