php - Specific example analysis of sql injection and xss

Question

My website was attacked a month ago, and today I received a vulnerability detection report from 360. Oh my God, 360 still does this kind of thing?

• sql injection
  Vulnerability link 1:
  http: //xxx.com:80/index.php?alias=message&action=comment?comment-diary-id=1&comment-ip=182.118. 33.8&comment-author=88888&comment-email=hacker@hacker.org&comment-url=http: //www.hacker.org/&comment-text=88888&comment-submit=SEND&comment-parent=0 RLIKE (SELECT (CASE WHEN (4725=4725 ) THEN 0 ELSE 0x28 END))
  Vulnerability link 2:
  http: //xxx.com:80/index.php?alias=message' AND SLEEP(5)
  # Vulnerability link 3:
  http: //xxx.com:80/index.php?cat=note' AND 'dSob'='dSob

• xss
  Vulnerability link:
  http: //xxx.com:80/admin/login.php?req_url=/admin/index.php"><script>alert(42873 )</script>

Why is it still injected when I use addslashes when writing to the database? Do link 1 and link 2 need to be combined to be injected?
As for the second vulnerability, I don't know how to defend against it.
I don’t have in-depth research on site security. I would like to ask you to analyze how this is achieved and how to fix the loopholes. Thank you.
If you need to write the code to the database, I will post it.

PS, writing links will be automatically shortened by sf, so a space is added after http:.

---

After debugging, it can indeed be injected...I still don’t know enough about sql

The final statement written to the database is:

insert into comment values(NULL,1,1497261734,'88888',0,'hacker@hacker.org','http://www.hacker.org/','182.118.33.8','88888',0 RLIKE (SELECT (CASE WHEN (4725=4725) THEN 0 ELSE 0x28 END)) AND SLEEP(5)%20%23);

I would like to ask what the last sentence means

0 RLIKE (SELECT (CASE WHEN (4725=4725) THEN 0 ELSE 0x28 END)) AND SLEEP(5)%20%23

Answer 1

xss nested html script code, parameters should be converted into html entities. Function htmlspecialchars

Connection 1 is to perform mysql by entering the mysql keyword. Now, you should need to filter the keyword.

Of course, the best way to prevent injection is to use preprocessing! ! ! !

Answer 2

1. It is best to use parameterized queries instead of splicing SQL statements.

2. xss can be filtered through parameters to filter out script codes like <script>.

Answer 3

Your code is not filtered at all