Preventing SQL Injections When WAF’s Not Enough (opens in new tab)

(cossacklabs.com)

18 pointsninegunpi7y ago13 comments

13 comments

Umh, this article is dubious.

1. If your WAF can be fooled by adding a X-Forwarded-For header, trouble ahead.

2. If your security strategy is about mitigating attacks where the payload matches some regular expressions, trouble ahead. Machine learning? Double trouble ahead.

3. If you don't write only completely static queries[1] to then use as prepared statements or use a proper ORM[2] when using a SQL database, trouble ahead.

[1] https://www.akadia.com/services/dyn_modify_where_clause.html

[2] Like linq, jOOQ...

ninegunpiOP7y ago

If your security strategy relies on one or two security controls, you're doomed most of the time.

We've added SQL filtering as a defense-in-depth measure, having a convenient seat in the architecture, complementing every other mitigation measure proper application developers and DBAs should be doing (and frequently get wrong).

Even ORMs get bypassed once in a while:

- https://github.com/mysqljs/mysql/issues/342 - https://github.com/sequelize/sequelize/issues/5671 - (okay, we can avoid this one by saying nothing "nothing proper exists in NodeJS world) https://bertwagner.com/2018/03/06/2-5-ways-your-orm-will-all...

Dumb concatenation can nullify the merit of quite advanced ORM: copybook example of misusing Ruby's ActiveRecord (is that proper enough) got as far as OWASP testing guide: https://www.owasp.org/index.php/Testing_for_ORM_Injection_(O...

Prepared statements are cooked wrong as well, but rarely, that's why they are viable line of defense, but not the sole one (as nothing should be):

https://www.reddit.com/r/netsec/comments/ww9qm/sqli_bypassin... https://stackoverflow.com/questions/134099/are-pdo-prepared-...

(in fact, I've seen with my eyes exactly what first comment in reddit postmentions).

all_blue_chucks7y ago

WAF's are never good enough. They're a weak band-aid used by companies who lack the expertise to find and fix security bugs in their own code.

Lt_Riza_Hawkeye7y ago

This is the correct answer. Unfortunately PCI dictates that you can use WAFs instead of real coding standards and testing.

For anyone curious why WAFs are so useless, there is a very beginner-accessible talk by Joe McCray here: https://www.youtube.com/watch?v=qBVThFwdYTc

wil4217y ago

The company I work at has many PCI compliant systems. I asked a security officer why they were still doing certain things the old way. He explained they very well know it’s the old way but in order to be compliant they must do it.

3 more replies

ris7y ago

This is an advertisement.

moutix7y ago

That's why we now have RASP. It's better than SQL proxy and WAF, because you have both the SQL query and the HTTP parameters and you can correlate them to be super accurate

ninegunpiOP7y ago

Isn't RASP just slapping the WAF-like signature detection into your application data streams directly? How would RASP prevent:

1. Insiders having access to database front?

2. Same SQL bypass techniques as employed to bypass WAFs?

3. Mitigate developer errors in query logic which enable custom injections?

j / k navigate · click thread line to collapse

13 comments

dullgiulio7y ago

Umh, this article is dubious.

1. If your WAF can be fooled by adding a X-Forwarded-For header, trouble ahead.

2. If your security strategy is about mitigating attacks where the payload matches some regular expressions, trouble ahead. Machine learning? Double trouble ahead.

3. If you don't write only completely static queries[1] to then use as prepared statements or use a proper ORM[2] when using a SQL database, trouble ahead.

[1] https://www.akadia.com/services/dyn_modify_where_clause.html

[2] Like linq, jOOQ...

ninegunpiOP7y ago

If your security strategy relies on one or two security controls, you're doomed most of the time.

Even ORMs get bypassed once in a while:

Prepared statements are cooked wrong as well, but rarely, that's why they are viable line of defense, but not the sole one (as nothing should be):

https://www.reddit.com/r/netsec/comments/ww9qm/sqli_bypassin... https://stackoverflow.com/questions/134099/are-pdo-prepared-...

(in fact, I've seen with my eyes exactly what first comment in reddit postmentions).

all_blue_chucks7y ago

WAF's are never good enough. They're a weak band-aid used by companies who lack the expertise to find and fix security bugs in their own code.

Lt_Riza_Hawkeye7y ago

This is the correct answer. Unfortunately PCI dictates that you can use WAFs instead of real coding standards and testing.

For anyone curious why WAFs are so useless, there is a very beginner-accessible talk by Joe McCray here: https://www.youtube.com/watch?v=qBVThFwdYTc

wil4217y ago

3 more replies

ris7y ago

This is an advertisement.

moutix7y ago

That's why we now have RASP. It's better than SQL proxy and WAF, because you have both the SQL query and the HTTP parameters and you can correlate them to be super accurate

ninegunpiOP7y ago

Isn't RASP just slapping the WAF-like signature detection into your application data streams directly? How would RASP prevent:

1. Insiders having access to database front?

2. Same SQL bypass techniques as employed to bypass WAFs?

3. Mitigate developer errors in query logic which enable custom injections?

j / k navigate · click thread line to collapse