1 1 00:00:00,360 --> 00:00:02,910 Sensitive Data Exposure. 2 2 00:00:02,910 --> 00:00:04,440 In this lesson, we're going to talk 3 3 00:00:04,440 --> 00:00:06,360 about sensitive data exposure, 4 4 00:00:06,360 --> 00:00:08,430 which is when a software vulnerability occurs 5 5 00:00:08,430 --> 00:00:09,750 that allows the attacker to be able 6 6 00:00:09,750 --> 00:00:11,640 to circumvent access controls 7 7 00:00:11,640 --> 00:00:13,830 and retrieve confidential or sensitive data 8 8 00:00:13,830 --> 00:00:16,050 from a file system or a database. 9 9 00:00:16,050 --> 00:00:19,170 Essentially, we're having a breach of confidentiality here 10 10 00:00:19,170 --> 00:00:21,600 so we want to make sure we don't have this happen. 11 11 00:00:21,600 --> 00:00:25,290 So how can we end up preventing sensitive data exposure? 12 12 00:00:25,290 --> 00:00:27,240 Well, we should program our web applications 13 13 00:00:27,240 --> 00:00:29,910 to only send data between authenticated hosts 14 14 00:00:29,910 --> 00:00:33,300 using cryptography and encryption to protect the session. 15 15 00:00:33,300 --> 00:00:36,600 Now, when it comes to encryption, what type should you use? 16 16 00:00:36,600 --> 00:00:38,610 Should you use your own encryption mechanism? 17 17 00:00:38,610 --> 00:00:41,010 Should you make something up because you're just that smart? 18 18 00:00:41,010 --> 00:00:43,500 No, you should use what everybody else is using. 19 19 00:00:43,500 --> 00:00:45,060 You should be using AES. 20 20 00:00:45,060 --> 00:00:46,290 You should be using other things 21 21 00:00:46,290 --> 00:00:48,060 that are widely known and widely tested 22 22 00:00:48,060 --> 00:00:50,400 because those have been proven to be secure. 23 23 00:00:50,400 --> 00:00:52,170 As smart as you may think you are, 24 24 00:00:52,170 --> 00:00:55,320 using your own encryption scheme is a recipe for disaster 25 25 00:00:55,320 --> 00:00:57,510 because our own encryption schemes aren't tested 26 26 00:00:57,510 --> 00:01:01,290 to the level that AES and other worldwide standards are. 27 27 00:01:01,290 --> 00:01:03,420 So we should really be using those worldwide standards 28 28 00:01:03,420 --> 00:01:06,510 as a best practice whenever we're using encryption. 29 29 00:01:06,510 --> 00:01:08,190 Now, another thing you need to avoid 30 30 00:01:08,190 --> 00:01:10,560 inside of your applications is the use 31 31 00:01:10,560 --> 00:01:12,210 of hardcoded credentials. 32 32 00:01:12,210 --> 00:01:14,190 This means you don't want to be able to put in things 33 33 00:01:14,190 --> 00:01:16,980 like your database credentials inside your web app 34 34 00:01:16,980 --> 00:01:19,410 or your usernames or your passwords or things like that. 35 35 00:01:19,410 --> 00:01:22,050 If you're typing them in plain text and hardcoding them in, 36 36 00:01:22,050 --> 00:01:25,290 even as a hash, that is something that could be taken 37 37 00:01:25,290 --> 00:01:26,610 and exploited against you. 38 38 00:01:26,610 --> 00:01:27,930 And this would be another thing that leads 39 39 00:01:27,930 --> 00:01:29,940 to sensitive data exposure. 40 40 00:01:29,940 --> 00:01:31,530 Another thing we always want to make sure we do 41 41 00:01:31,530 --> 00:01:34,890 is disable the use of client password autocomplete features, 42 42 00:01:34,890 --> 00:01:37,830 temporary files and cookies whenever possible. 43 43 00:01:37,830 --> 00:01:39,690 By doing this, we can reduce the risk 44 44 00:01:39,690 --> 00:01:41,580 of sensitive data exposure. 45 45 00:01:41,580 --> 00:01:44,010 Now, speaking of cookies, one more time, 46 46 00:01:44,010 --> 00:01:45,360 let's talk about cookies. 47 47 00:01:45,360 --> 00:01:48,360 There are five key areas inside of your cookies 48 48 00:01:48,360 --> 00:01:50,490 that you need to think about because these five areas 49 49 00:01:50,490 --> 00:01:52,620 and these five attributes are things 50 50 00:01:52,620 --> 00:01:54,510 that may offer client protection 51 51 00:01:54,510 --> 00:01:56,490 depending on how you set them up. 52 52 00:01:56,490 --> 00:01:58,530 First, we have secure. 53 53 00:01:58,530 --> 00:02:00,180 When we talk about the secure attribute, 54 54 00:02:00,180 --> 00:02:01,740 this instructs the client's web browser 55 55 00:02:01,740 --> 00:02:04,080 to only send the cookie if it's being sent 56 56 00:02:04,080 --> 00:02:06,780 over a secure channel like https. 57 57 00:02:06,780 --> 00:02:08,520 Basically, it requires encryption 58 58 00:02:08,520 --> 00:02:10,650 for you to be able to pass the cookie. 59 59 00:02:10,650 --> 00:02:13,320 Second, HttpOnly. 60 60 00:02:13,320 --> 00:02:15,750 This prevents attacks such as cross-site scripting 61 61 00:02:15,750 --> 00:02:18,210 because it disables access from client-side scripting 62 62 00:02:18,210 --> 00:02:19,320 to your cookie. 63 63 00:02:19,320 --> 00:02:20,940 The only way you can access the cookie 64 64 00:02:20,940 --> 00:02:23,070 is over http. 65 65 00:02:23,070 --> 00:02:24,720 Third, domain. 66 66 00:02:24,720 --> 00:02:26,730 This is going to set the domain of the server 67 67 00:02:26,730 --> 00:02:28,410 that the cookie is valid for. 68 68 00:02:28,410 --> 00:02:30,000 Cookies are only going to be able to be accessed 69 69 00:02:30,000 --> 00:02:32,070 from the domain or subdomains specified 70 70 00:02:32,070 --> 00:02:33,750 within this particular attribute 71 71 00:02:33,750 --> 00:02:36,540 so it really limits who can access that cookie. 72 72 00:02:36,540 --> 00:02:38,190 Fourth, path. 73 73 00:02:38,190 --> 00:02:40,200 This is going to specify the URL path 74 74 00:02:40,200 --> 00:02:41,910 for which the cookie is valid. 75 75 00:02:41,910 --> 00:02:43,230 Now, this may be the domain 76 76 00:02:43,230 --> 00:02:45,390 but it also might be a sub-part of the domain. 77 77 00:02:45,390 --> 00:02:48,690 For instance, you might have a cookie for diontrain.com, 78 78 00:02:48,690 --> 00:02:50,400 or it might be set to the path 79 79 00:02:50,400 --> 00:02:54,990 of diontrain.com/account/course/cysa 80 80 00:02:54,990 --> 00:02:56,910 or something like that. 81 81 00:02:56,910 --> 00:02:58,920 And fifth, expires. 82 82 00:02:58,920 --> 00:03:01,590 This is used to set persistent cookies that will expire 83 83 00:03:01,590 --> 00:03:03,810 at a certain date within this attribute. 84 84 00:03:03,810 --> 00:03:06,990 So I might set my cookie to expire after seven days, 85 85 00:03:06,990 --> 00:03:10,620 30 days, 60 days, a year, whatever it is. 86 86 00:03:10,620 --> 00:03:13,020 Just remember, the longer that you keep this, 87 87 00:03:13,020 --> 00:03:15,420 the more chance there is the data inside that cookie 88 88 00:03:15,420 --> 00:03:16,473 could be accessed.