SolarWinds Serv-U FTP Server 15.2.1 Cross Site Scripting

`Title: Stored XSS  
  
  
  
Product: SolarWinds Serv-U FTP Server  
  
  
  
Vendor Homepage: https://www.solarwinds.com/  
  
  
  
Vulnerable Version: 15.2.1 and lower  
  
  
  
Fixed Version: 15.2.2  
  
  
  
CVE Number: CVE-2020-28001  
  
  
  
Author: Jack Misiura from The Missing Link   
  
  
  
Website: https://www.themissinglink.com.au  
  
  
  
Timeline:  
  
  
  
2020-10-30 Disclosed to Vendor  
  
2021-01-21 Vendor releases patched version  
  
2021-08-02 Publication  
  
  
  
1. Vulnerability Description  
  
  
  
SolarWinds Serv-U FTP server through 15.2.1 does not correctly sanitize and validate the user-supplied directory names, allowing malicious users to create directories that when clicked on (in the breadcrumb menu) will trigger XSS payloads.  
  
  
  
2. PoC  
  
  
  
On a vulnerable Serv-U FTP server installation, create a directory named as such:  
  
  
  
%27%29%3Ba%3Dfunction%28b%29%20%7B%20alert%28%22XSS%22%29%3B%20%7D%3Ba%28%27  
  
  
  
The payload contains ');a=function(b) { alert("XSS"); };a('  
  
  
  
As soon as a user clicks on the directory name in the breadcrumb menu, it will trigger the stored XSS.  
  
  
  
3. Solution  
  
  
  
The vendor provides an updated version (15.2.2) which should be installed immediately.  
  
  
  
4. Advisory URL  
  
  
  
https://www.themissinglink.com.au/security-advisories  
  
  
  
  
  
  
  
  
Jack Misiura​  
  
  
Application Security Consultant  
  
  
  
  
a  
  
  
  
9‑11 Dickson Avenue  
  
  
Artarmon  
  
  
NSW  
  
  
2064  
  
  
  
p  
  
  
1300 865 865  
  
  
  
os  
  
  
+61 2 8436 8585  
  
  
  
w  
  
  
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