Abyss WebServer Brute Force Vulnerability

[thomas adams <tgadams () bellsouth net>]

Abyss WebServer Brute Force Vulnerability

Package:                Abyss WebServer 
Vendor Web Site:        http://www.aprelium.com
Versions:               All versions <= v1.1.2
Platforms:              Linux, Windows
Local:                  No
Remote:                 Yes
Fix Available:          No(fix in progress)
Vendor Contacted:       Sunday, February 09, 2003 6:12 PM
Advisory Author:        thomas adams(tgadams () bellsouth net)



Background:
Abyss Web Server is a free, easily configured web server designed for 
Windows and Linux operating systems. The vendor, Aprelium, targets small 
businesses and personal use with this "fast, small and easy to use" 
server. The main feature is a remote web management interface where a user 
can configure the server in a matter of minutes. 


Exploit:
By connecting to the remote web management interface at 
http://abyss_server:9999 an attacker can use a brute-force method to gain 
access to the server. There is no delay in a wrong attempt and attackers
are given an indefinite number of attempts at entering a valid user and 
password. Unlike the access.log file for port 80, Abyss has no logging for 
port 9999. This allows an attacker to perform unseen.


Vendor Response: 
Aprelium was notified and will soon release an updated version of the 
server to include a fix for the brute-force attack and logging of port 
9999. The vendor was also notified of several directories and files
having write priviledges. It was agreed that a user should set permissions 
themselves, but there is no documentation telling a user what has write 
access by default. Aprelium has also decided to add a fix for the default 
permissions of directories and files.