CVE-2024-56828 Information

Description

File Upload vulnerability in ChestnutCMS through 1.5.0. Based on the code analysis it was determined that the /api/member/avatar API endpoint receives a base64 string as input. This string is then passed to the memberService.uploadAvatarByBase64 method for processing. Within the service the base64-encoded image is parsed. For example given a string like: data:image/html;base64PGh0bWw+PGltZyBzcmM9eCBvbmVycm9yPWFsZXJ0KDEpPjwvaHRtbD4= the content after the comma is extracted and decoded using Base64.getDecoder().decode(). The substring from the 11th character up to the first occurrence of a semicolon (;) is assigned to the suffix variable (representing the file extension). The decoded content is then written to a file. However the file extension is not validated and since this functionality is exposed to the frontend it poses significant security risks.

Reference

https://gitee.com/liweiyi/ChestnutCMS https://github.com/Zerone0x00/CVE/blob/main/ChestnutCMS/CVE-2024-56828.md https://www.1000mz.com/