CVE-2020-37113Public exploitNetwork attack vector

Authenticated code execution via extension filter bypass

Published Feb 3, 2026 · Updated Feb 3, 2026

Unrestricted file upload in GUnet Open eClass 1.7.3 allows remote authenticated users to execute arbitrary server-side code. The exercise submission feature renames .php uploads to .phps but accepts case variants such as .PhP and alternate PHP extensions such as .php3, leaving the uploaded shell executable. A student account and enrollment in a class accepting exercise submissions are required; successful exploitation runs the web shell with the web server's privileges.

CVSS severity8.7
High
EPSS probability0.81%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Unrestricted file upload in GUnet Open eClass 1.7.3 allows remote authenticated users to execute arbitrary server-side code. The exercise submission feature renames .php uploads to .phps but accepts case variants such as .PhP and alternate PHP extensions such as .php3, leaving the uploaded shell executable. A student account and enrollment in a class accepting exercise submissions are required; successful exploitation runs the web shell with the web server's privileges.

The record

CVE
CVE-2020-37113
Published
Feb 3, 2026
Updated
Feb 3, 2026
Vendor
GUnet
Product
Open eClass
Classifications
CWE-434, T1505.003
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 3, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 3, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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  1. Affected versionversion=1.7.3 (2007)

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

GUnet · Open eClassversion=1.7.3 (2007)

Published CVSS scores

8.8VulnCheckCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
8.7VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA: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.

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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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-434Unrestricted Upload of File with Dangerous Type
T1505.003Server Software Component: Web Shell

Public exploit references

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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