Sony BRAVIA Smart TV Denial Of Service

2019.07.09
Credit: xen1thLabs
Risk: Medium
Local: No
Remote: Yes
CWE: N/A

## 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/


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