> For the complete documentation index, see [llms.txt](https://docs.cooku222.kr/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.cooku222.kr/security/web-hacking/lord-of-sql-injection/lord-of-sqlinjection-ouroboros.md).
# \[Lord Of SQLInjection] ouroboros
```
if(preg_match('/prob|_|\.|rollup|join|@/i', $_GET['pw'])) exit("No Hack ~_~");
```
pw에 필터링 목록이 있다면 No Hack 을 출력하고 종료함
```
$query = "select pw from prob_ouroboros where pw='{$_GET[pw]}'";
echo "query : {$query} ";
```
\- 필터링에 걸리지 않았다면 select pw from prob\_ouroboros where pw=’{$\_GET\[pw]}’에 삽입됨
\- 그 후 삽입된 쿼리문을 출력함
```
$result = @mysqli_fetch_array(mysqli_query($db, $query));
if($result['pw']) echo "
Pw: {$result[pw]}
';
if(($result['pw']) && ($result['pw'] === $_GET['pw'])) solve("ouroboros");
```
\- 쿼리문의 결과값 pw이 있다면 출력한다.
\- 그 후 결과값 pw와 입력한 pw이 같다면 클리어 함
####
#### Solution
```
select pw from 'prob_ourobors' where pw='' union select '테스트입니당';
```
\- Quine SQL 이란?
-> Quine은 소스코드를 그대로 출력으로 반환하는 프로그램을 의미
-> Quine SQL은 입력된 쿼리문을 그대로 반환하는 것으로 생각
---
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