nanog mailing list archives

Re: Second day of rolling blackouts starts


From: Marshall Eubanks <tme () 21rst-century com>
Date: Fri, 19 Jan 2001 09:43:18 -0500


Two people have asked me off list about the RAMEN worm,
which affects Linux Redhat distro's. Here is brief description of the
worm, and a link to more,
from Lucy Lynch at Internet2 / UOregon.

The multicast implications :

This worm scans a portion of the multicast address space. These scans (packets)
are viewed as new multicast sources by a PIM multicast enabled router,
which encapsulates
them and sends them to its RP. The RP creates MSDP Session Announcements
FOR EACH SCAN 
and floods them to every RP neighbor it has in "nearby" AS's, and those
repeat the process.
The result is a MSDP packet storm. We have gotten 15,000 SA's a minute.
Dealing with these
can melt down routers. (We had to reboot a Cisco 7204, for example,
which apparently either filled
up or fragmented its memory beyond usability.)

I think it is fair to say that the question of rate limiting and other
DOS filtering in
PIM/SSM/MSDP multicast is getting serious attention now.

Marshall Eubanks


"Lucy E. Lynch" wrote:

a bit more info on ramen here:

http://members.home.net/dtmartin24/ramen_worm.txt

"And now, the contents of that ramen.tgz file: All the binaries are in the
archive twice, with RedHat 6.2 and RedHat 7.0 versions. Numerous binaries
were not stripped, which makes the job of taking them apart easier."

asp:       An xinetd config. file that will start up the fake webserver
           Used on RedHat 7.0 victim machines.
asp62:     HTTP/0.9-compatible server that always serves out the file
           /tmp/ramen.tgz to any request - NOT stripped
asp7:      RedHat 7-compiled version - NOT stripped
bd62.sh:   Does the setup (installing wormserver, removing vulnerable
           programs, adding ftp users) for RedHat 6.2
bd7.sh:    Same for RedHat 7.0
getip.sh:  Utility script to get the main external IP address
hackl.sh:  Driver to read the .l file and pass addresses to lh.sh
hackw.sh:  Driver to read the .w file and pass addresses to wh.sh
index.html: HTML document text
l62:       LPRng format string exploit program - NOT stripped
l7:        Same but compiled for RedHat 7 - stripped
lh.sh:     Driver script to execute the LPRng exploit with several
           different options
randb62:   Picks a random class-B subnet to scan on - NOT stripped
randb7:    Same but compiled for RedHat 7 - NOT stripped
s62:       statdx exploit - NOT stripped
s7:        Same but compiled for RedHat 7 - stripped
scan.sh:   get a classB network from randb and run synscan
start.sh:  Replace any index.html with the one from the worm; run getip;
           determine if we're RedHat 6.2 or 7.0 and run the appropriate
           bd*.sh and start*.sh
start62.sh: start (backgrounded) scan.sh, hackl.sh, and hackw.sh
start7.sh:  Same as start62.sh
synscan62:  Modified synscan tool - records to .w and .l files - stripped
synscan7:   Same but compiled for RedHat 7 - stripped
w62:        venglin wu-ftpd exploit - stripped
w7:         Same but compiled for RedHat 7 - stripped
wh.sh:     Driver script to call the "s" and "w" binaries against a given
           target
wu62:      Apparently only included by mistake.  "strings" shows it to be
           very similar to w62; nowhere is this binary ever invoked.

Lucy E. Lynch                           Academic User Services
Computing Center                        University of Oregon
llynch () darkwing uoregon edu             (541) 346-1774
Cell: (541) 912-7998                    5419127998 () mobile att net


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