COMMAND
AdCycle
SYSTEMS AFFECTED
AdCycle
PROBLEM
Mark Lastdrager posted following. "The Pike" pointed us at a
problem in the AdCycle banner management system. When the
installation of AdCycle is not completed carefully, a malicious
user may be able to obtain the management username/password.
Adcycle is a banner management system which is written in Perl and
uses MySQL for data storage. Installation is done by editing
AdConfig.pm, creating a Mysql user/password/database and then
running the build.cgi script. That script checks if the database
connection is working (showing the username/password it reads
from AdConfig.pm) and creating the tables within the database.
The 'exploit' is quite simple: when the build.cgi remains
executable for your httpd process after the installation, every
internet user can view the output of it, including your manager
password and database password. Attackers can delete, change and
add banner campaigns. Another big problem is when build.cgi is
called from a webbrowser, the AdCycle tables are dropped so all
bannercampaigns are lost.
SOLUTION
The installation instructions say you should set the build.cgi
permissions to 750. That will prevent some problems ofcourse,
but is far from totally secure. When the owner of the scripts
for example has the same gid as the httpd process, build.cgi is
still executable for the evil outside world. Everyone should
remove all bits from build.cgi after a succesful install, or
even completely remove it. Maybe the AdCycle makers planned to
put that advice in chapter 12 of the UNIX installation notes,
which seems to be missing.