multiple remote & local buffer overflows discovered in Drcatd
Zone-h Security Advisory
Date of discovery : 24 june 2004
Date of release : 25 june 2004
Bug found by Khan Shirani
<shirani@xxxxxxxxxx>
http://www.zone-h.org
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Software : Drcatd
Bugs : Buffer Overflows , Remote and local (multiple)
Risk : low
Platform : *nix
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Description:
============
Dr.Cat (Dave's Remote Cat) concatenates a file on a remote Linux host that is
running the
Dr.Cat daemon (drcatd) to stdout in the clients terminal. It authenticates
users versus
the standard shadow password authentication facility and spawns a process with
that users
permissions to attempt to access the requested file
http://www.joltedweb.com/drcat/
Vulnerability:
==============
Muliple local buffer overflows have been discovered . In addition to this ,
remote exploitation
is also possible due to a lack of boundry checking of input once a user has
been authenticated.
The vulnerability exists when the remote user sends an overly long filename
that doesnt exist.
This is handled by an sprintf() call which is where the overflow will occur
vulnerable code:
================
----------------------
drcat-0.5.0-beta\src\drcatd.c
sprintf(fdne_msg, "%s - File Does Not Exist", buf);
logIt(fdne_msg);
sprintf(fd_msg, "%s - File Does Not Exist\n", buf);
len = sizeof(fd_msg);
local_send(new_fd, fd_msg, len);
exit(1);
----------------------
NOTE: Due to the exit(1) from the above snippet, exploitation of this
vulnerability is not possible within x86 arche's.
Vendor Notice:
==============
The vendor has been notified via <dave@xxxxxxxxxxxxx>
Copyright
=========
Contents may not be altered without notification to original author
permission is granted to reproduce this advisory on public databases.
shirani@xxxxxxxxxx
and all the zone-h staff.
http://www.zone-h.org