What is the CVSS score of CVE-2024-56828?

CVE-2024-56828 has a CVSS 3.1 base score of 9.8 (Critical). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.1%.

Which versions of Chestnutcms are affected by CVE-2024-56828?

Organizations using ChestnutCMS face critical risk from CVE-2024-56828, a unrestricted file upload vulnerability rated CVSS 9.8.

Is there a public PoC exploit available for CVE-2024-56828?

Yes, a public proof-of-concept exploit is available for CVE-2024-56828. Prioritise patching immediately. EPSS: 0.1%.

How to fix or mitigate CVE-2024-56828?

Within 24 hours: Identify all affected systems running ChestnutCMS and apply vendor patches immediately. Review file handling controls and restrict upload directories.

Chestnutcms CVE-2024-56828

CRITICAL

Unrestricted Upload of File with Dangerous Type (CWE-434)

2025-01-06 cve@mitre.org

File Upload Chestnutcms 1000Mz

9.8

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

9.8 CRITICAL

AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Analysis Generated

Mar 28, 2026 - 18:02 vuln.today

PoC Detected

Apr 21, 2025 - 17:10 vuln.today

Public exploit code

CVE Published

Jan 06, 2025 - 18:15 nvd

CRITICAL 9.8

DescriptionCVE.org

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.

AnalysisAI

File Upload vulnerability in ChestnutCMS through 1.5.0. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.

Technical ContextAI

This vulnerability is classified as Unrestricted File Upload (CWE-434), which allows attackers to upload malicious files that can be executed on the server. 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 products include: 1000Mz Chestnutcms. Version information: through 1.5.0..

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Validate file types server-side, store uploads outside webroot, use random filenames, scan for malware.