Nginx 和 ModSecurity

Question

I'm having a strange issue with Ubuntu 18.04 and Nginx with ModSecurity. I've compiled everything correctly and it's working when activating the ModSecurity module, however whenever I activate a rule, I get the following:

terminate called after throwing an instance of 'std::logic_error'
  what():  basic_string::_M_construct null not valid

Nginx crashes and doesn't serve the page - any ideas?

Answer 1

I'm having this issue in Ubuntu 16.04 as well. This seems to be an issue with the latest version of ModSecurity as seen in this bug: https://github.com/SpiderLabs/ModSecurity/issues/2180

If you downloaded ModSecurity via git, you can use this command to get back to a working version:

git reset --hard d5b93c1013ca9c9a96c75369576b54832e9a2b48

Then clean your ModSecurity build directory and build it again. Once you have ModSecurity rebuild, restart nginx. Once the above bug is closed in GitHub, it will probably be safe to update to the latest version again.