External risk intelligence

School Management Arbitrary File Upload Leading to Web Shell

CVE advisorySeverity: CRITICAL (CVSS 9.9)

CVE-2025-31100

The vulnerability exists in a web-based school management application. Such applications are commonly deployed as internet-facing web portals to facilitate access for students, parents, and faculty, making the web interface and its associated file upload functions frequently accessible via the public internet.

Unrestricted File Upload

Halo Surface Signal: 4 out of 5 — likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

This CVE describes an unrestricted file upload vulnerability in a school management system, allowing attackers to upload malicious files to the web server. The concern is the potential for unauthorized code execution and system compromise if the affected system is internet-facing.

Attackers can upload harmful files.
This could allow unauthorized system control.
Confirm if our school management system is affected.

Attack Path

How an attacker could exploit the issue

An attacker with login access to the School Management system could upload a malicious file. This file could then be used to execute commands on the server, potentially leading to a full compromise of the web server.

Requires authenticated user access.
Uploading a specially crafted file.
Allows remote code execution.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability in a school management application could allow an unauthenticated user to upload a web shell to the server. This may lead to the attacker gaining control over the web server, impacting the availability and integrity of the application and its hosted data.

Server-side code execution.
Uploading a malicious file.
Compromise of the school's system.

Operational Fix

Recommended remediation, mitigation, and detection steps

This vulnerability in the School Management application requires action from the platform or infrastructure team responsible for deploying and managing the web server, as well as the application owner who oversees the School Management software. The first critical step is to identify all instances of the affected School Management application, determine their internet reachability and business criticality, and then confirm the accountable owner for each instance to prioritize remediation efforts.

Platform/Application owners are responsible.
Verify internet-facing instances and criticality.
Plan remediation based on identified risk.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

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Frequently asked questions

What is the Mojoomla School Management software?

Mojoomla School Management is a web-based application designed to help educational institutions organize and automate administrative tasks. It functions as a central portal where students, parents, and faculty log in to manage school-related activities, records, and communications through a browser-based interface.

What does CWE-434 mean regarding CVE-2025-31100?

CWE-434 refers to the Unrestricted Upload of File with Dangerous Type. In the context of this CVE, it means the application does not properly validate or restrict the types of files users can upload. Because the system fails to verify file extensions or content, an attacker can upload a malicious script—often called a web shell—that the server then treats as an executable file.

How does an attacker trigger this vulnerability?

An attacker triggers this bug by logging into the School Management system and using the application's file upload feature to send a malicious file to the server. Simply browsing the site or sending non-file requests will not trigger the vulnerability; it specifically requires a user with valid credentials to complete the upload process with a specially crafted file.

Is my instance at risk according to Halo Surface Signal?

Halo Surface Signal indicates that School Management applications are often deployed as internet-facing portals to support remote access for students and staff. Because these systems are frequently exposed to the public internet to remain accessible, they are considered highly likely to be reachable by external attackers who may attempt to exploit this file upload weakness.

What should I do if I run this technology?

First, identify all servers running the School Management software to determine which instances are active. Once you have an inventory, assess which systems are reachable via the internet versus those confined to an internal network. Coordinate with your application owners to confirm the version installed and prioritize securing or updating any internet-facing instances to prevent unauthorized access.

References

patchstack.com/database/wordpress/plugin/school-management/vulnerabi…

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.