mirror of
https://github.com/swisskyrepo/PayloadsAllTheThings.git
synced 2024-12-20 03:16:10 +00:00
36 lines
1.4 KiB
Markdown
36 lines
1.4 KiB
Markdown
|
# Regular Expression
|
||
|
|
|
||
|
|
> Regular Expression Denial of Service (ReDoS) is a type of attack that exploits the fact that certain regular expressions can take an extremely long time to process, causing applications or services to become unresponsive or crash.
|
||
|
|
|
||
|
|
|
||
|
|
## Denial of Service - ReDoS
|
||
|
|
|
||
|
|
* [tjenkinson/redos-detector](https://github.com/tjenkinson/redos-detector) - A CLI and library which tests with certainty if a regex pattern is safe from ReDoS attacks. Supported in the browser, Node and Deno.
|
||
|
|
* [doyensec/regexploit](https://github.com/doyensec/regexploit) - Find regular expressions which are vulnerable to ReDoS (Regular Expression Denial of Service)
|
||
|
|
* [devina.io/redos-checker](https://devina.io/redos-checker) - Examine regular expressions for potential Denial of Service vulnerabilities
|
||
|
|
|
||
|
|
|
||
|
|
### Evil Regex
|
||
|
|
|
||
|
|
Evil Regex contains:
|
||
|
|
|
||
|
|
* Grouping with repetition
|
||
|
|
* Inside the repeated group:
|
||
|
|
* Repetition
|
||
|
|
* Alternation with overlapping
|
||
|
|
|
||
|
|
**Examples**
|
||
|
|
|
||
|
|
* `(a+)+`
|
||
|
|
* `([a-zA-Z]+)*`
|
||
|
|
* `(a|aa)+`
|
||
|
|
* `(a|a?)+`
|
||
|
|
* `(.*a){x}` for x \> 10
|
||
|
|
|
||
|
|
These regular expressions can be exploited with `aaaaaaaaaaaaaaaaaaaaaaaa!`
|
||
|
|
|
||
|
|
|
||
|
|
## References
|
||
|
|
|
||
|
|
* [Regular expression Denial of Service - ReDoS - OWASP - Adar Weidman](https://owasp.org/www-community/attacks/Regular_expression_Denial_of_Service_-_ReDoS)
|
||
|
|
* [OWASP Validation Regex Repository - OWASP](https://wiki.owasp.org/index.php/OWASP_Validation_Regex_Repository)
|