CVE-2018-18830

CRITICAL

MCMS 4.6.5 - Unauthenticated Arbitrary File Upload via FileAction.java

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2018-18830. PoCs published by mingSoft.

AI-analyzed exploit summary The writeup describes an unauthorized file upload vulnerability in MCMS where the upload interface lacks authentication checks, allowing attackers to upload malicious files (e.g., JSP webshells) by manipulating the file extension in the request. The attack involves intercepting and modifying the 'name' parameter to bypass restrictions.

Description

An issue was discovered in com\mingsoft\basic\action\web\FileAction.java in MCMS 4.6.5. Since the upload interface does not verify the user login status, you can use this interface to upload files without setting a cookie. First, start an upload of JSP code with a .png filename, and then intercept the data packet. In the name parameter, change the suffix to jsp. In the response, the server returns the storage path of the file, which can be accessed to execute arbitrary JSP code.

Exploits (1)

gitee WRITEUP 32,018 stars
by mingSoft · javawriteup
https://gitee.com/mingSoft/MCMS/issues/IO0IQ

The writeup describes an unauthorized file upload vulnerability in MCMS where the upload interface lacks authentication checks, allowing attackers to upload malicious files (e.g., JSP webshells) by manipulating the file extension in the request. The attack involves intercepting and modifying the 'name' parameter to bypass restrictions.

Classification
Writeup 80%
Attack Type
Auth Bypass
Complexity
Trivial
Reliability
Reliable
Target: MCMS (MingSoft Content Management System)
No auth needed
Prerequisites: Network access to the target MCMS instance · Ability to intercept/modify HTTP requests
devstral-2 · analyzed Mar 04, 2026 Full analysis →

References (1)

Core 1
Core References
Third Party Advisory x_refsource_misc
https://gitee.com/mingSoft/MCMS/issues/IO0IQ

Scores

CVSS v3 9.8
EPSS 0.0041
EPSS Percentile 62.0%
Attack Vector NETWORK
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Details

CWE
CWE-434
Status published
Products (2)
mingsoft/mcms 4.6.5
net.mingsoft/ms-mcms 0Maven
Published Oct 30, 2018
Tracked Since Feb 18, 2026