CVE-2024-56828: 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…

PriorityP356critical9.8CVSS 3.1

AVNACLPRNUINSUCHIHAH

EPSS

0.85%

53.6th percentile

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;base64,PGh0bWw+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.

Affected

1 ranges

Vendor	Product	Version range	Fixed in
1000mz	chestnutcms	<= 1.5.0	—

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