Overview
Today, we tackle a critical vulnerability identified as CVE-2025-55383, which affects the Moss platform before v0.15. This vulnerability is of utmost concern as it allows attackers to upload files with any extension to any location on the target server. Such a vulnerability can potentially compromise a system or lead to significant data leakage, thereby posing a serious threat to the confidentiality, integrity, and availability of data.
This vulnerability stands out due to its high severity score, which is an alarming 8.6. This score indicates the potential damage it can cause if left unpatched. For organizations relying heavily on Moss for their operations, this vulnerability is a ticking time bomb that needs immediate attention.
Vulnerability Summary
CVE ID: CVE-2025-55383
Severity: High (8.6)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: System compromise and potential data leakage
Affected Products
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Product | Affected Versions
Moss | Before v0.15
How the Exploit Works
The exploit takes advantage of a misconfiguration in the “upload” function of Moss. This misconfiguration allows an attacker to bypass security restrictions and upload files of any extension to any location on the target server. The attacker can upload a malicious script or executable file, which can then be executed to compromise the system or to leak sensitive data.
Conceptual Example Code
The following is a conceptual example of how an attacker might exploit this vulnerability. This is a sample HTTP POST request to upload a malicious file to the server:
POST /upload/file HTTP/1.1
Host: target.example.com
Content-Type: multipart/form-data; boundary=----WebKitFormBoundary7MA4YWxkTrZu0gW
------WebKitFormBoundary7MA4YWxkTrZu0gW
Content-Disposition: form-data; name="file"; filename="malicious_script.sh"
Content-Type: application/x-sh
{ "malicious_script": "..." }
------WebKitFormBoundary7MA4YWxkTrZu0gW--Mitigation
The best mitigation for this vulnerability is to apply the vendor patch. It is strongly recommended to upgrade to a version of Moss that is v0.15 or later. Until the patch can be applied, a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can be used as a temporary mitigation measure. These systems can be configured to block or alert on suspicious file uploads that may be attempts to exploit this vulnerability.
