Forum Discussion
Log4j iRule mitigation as described in K59329043 - which encoding is the regex using ?
Hi
thank you for clarifying the trade off idea behind.
What I'm still missing here is the encoding part used when performing the Regex comparison - as mentioned in the initial post, I'm seeing some false positives within the application payload. This forced me to manually add some whitelisting within the originally provided iRule.
I've attempted to dump the payload as collected by the "HTTP_REQUEST_DATA" event and have it checked against the reference regex (tcl based regex checking - using the f5 built-in tclsh interpreter for ex.) in order to better understand what is exactly matching the Regex - yet I'm seeing no matches.
So clearly I'm missing out on the encoding part.
Can you perhaps also advice on this ?
Thank you and Best Regards
Hi ,
looking only at this part (\$|\\+(0?44|([u0]00|x)24))
I can recognise the literal $.
The octal of $, which ist 44.
The hexadecimal of $, which is 24.
And some more characters in between.
And I would not claim that I am good at reading regex... Someone more savvy can for sure explain you in more details.
KR
Daniel
Recent Discussions
Related Content
* Getting Started on DevCentral
* Community Guidelines
* Community Terms of Use / EULA
* Community Ranking Explained
* Community Resources
* Contact the DevCentral Team
* Update MFA on account.f5.com