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## ADVISORY INFORMATION  
  
TITLE: Two vulnerabilities found in Sony BRAVIA Smart TVs  
ADVISORY URL:  
CVE-2019-11889  
https://www.darkmatter.ae/xen1thlabs/sony-remote-denial-of-service-triggered-over-vulnerability-hbbtv-xl-19-014/  
CVE-2019-11890  
https://www.darkmatter.ae/xen1thlabs/sony-remote-denial-of-service-over-wifi-lan-internet-vulnerability-xl-19-013/  
  
DATE PUBLISHED: 02/07/2019  
AFFECTED VENDORS: Sony  
RELEASE MODE: Coordinated release  
CVE: CVE-2019-11889, CVE-2019-11890  
CVSSv3 for CVE-2019-11889: 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)  
CVSSv3 for CVE-2019-11890: 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)  
  
## PRODUCT DESCRIPTION  
BRAVIA is a brand of Sony Visual Products known as Smart TVs.   
These Smart TVs are known to be high standard products.  
  
  
## DETAILS OF VULNERABILITIES  
xen1thLabs has found two vulnerabilities in Sony products and coordinated   
the disclosure of these security flaws with Sony. The vulnerabilities have   
been found in the Sony Bravia Smart TV by xen1thLabs while auditing the   
security of Smart TVs. The list of affected models has not been shared by Sony.   
xen1thLabs tested several Sony Bravia Smart TVs.  
  
The summary of the vulnerabilities is:  
  
- CVE-2019-11889 Sony Remote Denial-of-Service Triggered Over HbbTV   
Vulnerability:  
This vulnerability allows an attacker to remotely crash the HbbTV rendering   
engine and block the TV  
  
- CVE-2019-11890 Sony Remote Denial-of-Service Over Wifi / LAN / Internet  
Vulnerability:  
This vulnerability allows an attacker to remotely crash the Smart TV using  
TCP packets.  
  
### 1. CVE-2019-11889 Sony Remote Denial-of-Service Triggered Over HbbTV   
Vulnerability  
By sending a specifically crafted webpage over HbbTV it is possible to freeze the   
television remotely. (please see the presentation at HiTB Dubai 2018 for HbbTV description   
https://conference.hitb.org/hitbsecconf2018dxb/sessions/hacking-into-broadband-and-broadcast-tv-systems/),   
  
The remote control does not appear to work except the PROG+ and PROG- buttons.   
Only changing channels allows to 'un-freeze' the television. Android is supposed   
to kill blocked applications.  
  
In order to reproduce the behavior, start by generating a webpage using:   
  
```  
dd if=/dev/zero of=index.html bs=1M count=2048  
````  
  
Using the software-defined radio, send a DVB-T signal containing a HbbTV application that force   
the targeted Smart TV to load a file from a controlled server. By forcing the Smart TV to load   
the generated file, it can be observed from the logs, only between 180KB and 250KB are served   
before the HbbTV application freezes:  
  
```  
vaccess.log:127.0.1.1:80 192.168.1.191 - - [01/Apr/2019:06:40:54 -0400] "GET /hbbtvtest/test3/ HTTP/1.1"   
200 178647 "http://x.test/hbbtvtest/index.php" "Mozilla/5.0 (Linux armv7l) AppleWebKit/537.36 (KHTML, like Gecko)   
Chrome/42.0.2311.152 Safari/537.36 OPR/29.0.1803.0 OMI/4.5.23.37.ALSAN5.131 HbbTV/1.2.1 (; Sony; KD-65X7500D; v1.000000000; 2016;)   
sony.hbbtv.tv.2016HE"  
````  
  
```  
vaccess.log.1:127.0.1.1:80 192.168.1.191 - - [01/Apr/2019:02:36:16 -0400] "GET /hbbtvtest/test3/ HTTP/1.1"   
200 170543 "http://x.test/hbbtvtest/index.php" "Mozilla/5.0 (Linux armv7l) AppleWebKit/537.36 (KHTML, like Gecko)   
Chrome/42.0.2311.152 Safari/537.36 OPR/29.0.1803.0 OMI/4.5.23.37.ALSAN5.131 HbbTV/1.2.1 (; Sony; KD-65X7500D; v1.000000000; 2016;)   
sony.hbbtv.tv.2016HE"  
````  
Sony investigated the issue and shared the following analysis:  
"MITM attack by http connection is caused by the specification of the HbbTV service".   
  
### 2. CVE-2019-11890 Sony Remote Denial-of-Service Over Wifi / LAN / Internet Vulnerability  
  
An unauthenticated remote attacker can synflood the Smart TV over LAN and Wi-Fi, the smart   
television freezes and becomes irresponsive, some programs crash and the television reboots   
randomly. No PoC is released due to low complexity level of exploitation as Sony is not   
planning to release a security patch.  
  
Sony investigated the issue and shared the following analysis:  
"The Sony Product teams have conducted additional research regarding the submission and   
identified the following: CVE-2019-1189: DoS over WiFi /LAN - This is due to the performance   
of the interrupt operation in the Linux driver".  
  
## SOLUTION  
Sony provided the following recommendation:  
"Sony's manual instructs users to: Make sure to connect to the Internet or home network   
via a router, which will minimize this risk. In addition, these two symptoms can be   
recovered by unplugging the power supply cable. The TV cannot be broken and there is no   
internal data that can be stolen by these actions." (May 30th, 2019).  
  
And informed xen1thLabs that:  
"we will not be releasing any notifications." (June 19th, 2019).  
  
## DISCLOSURE TIMELINE  
01/04/2019 - Vulnerabilities have been found by xen1thLabs  
28/04/2019 - xen1thLabs send the report to Sony through their HackerOne Bug bounty program  
02/05/2019 - Updates requested from xen1thLabs through HackerOne  
10/05/2019 - Vulnerabilities have been confirmed by Sony through HackerOne  
14/05/2019 - xen1thLabs requests a CVE from MITRE  
30/05/2019 - Sony inform xen1thLabs of the solutions recommended for users through HackerOne  
30/05/2019 - xen1thLabs request the confirmation from Sony that no security patches will be provided through HackerOne  
07/06/2019 - Sony informs the following "Due to the evaluation conducted by our product team we will be closing out this ticket" through HackerOne  
26/06/2019 - Public disclosure  
  
## CREDITS  
xen1thLabs - Telecom Lab  
  
## REFERENCES  
  
CVE-2019-11889  
https://www.darkmatter.ae/xen1thlabs/sony-remote-denial-of-service-triggered-over-vulnerability-hbbtv-xl-19-014/  
  
CVE-2019-11890  
https://www.darkmatter.ae/xen1thlabs/sony-remote-denial-of-service-over-wifi-lan-internet-vulnerability-xl-19-013/  
  
Sony will not publish any security advisory nor release any security patch.  
  
## ABOUT xen1thLabs  
xen1thLabs conducts vulnerability research, which feeds in the testing and  
validation activities it conducts across software, hardware and  
telecommunication.  
  
xen1thLabs houses a team of world-class experts dedicated to providing  
high impact capabilities in cyber security.  
  
At xen1thLabs we are committed to uncovering new vulnerabilities that combat  
tomorrow's threats today.  
  
More information about xen1thLabs can be found at:  
https://www.darkmatter.ae/xen1thlabs/  
  
  
## WORKING AT xen1thLabs  
xen1thLabs is looking for several security researchers across multiple disciplines.  
Join a great team of likeminded specialists and enjoy all that UAE has to offer!  
  
If you are interested please visit:  
https://www.darkmatter.ae/xen1thlabs/