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Troubleshooting

Logs

When troubleshooting, the logs are your best friends. We try our best to provide user-friendly logs to help you understand what's happening.

Please note that you can set LOG_LEVEL setting to info (default : notice) to increase the verbosity of BunkerWeb.

Here is how you can access the logs depending on your integration :

List containers

To list the running containers you can use the following command : shell docker ps

You can use the docker logs command (replace mybunker with the name of your container) : shell docker logs mybunker

Here is the docker-compose equivalent (replace mybunker with the name of the services declared in the docker-compose.yml file) : shell docker-compose logs mybunker

List containers

To list the running containers you can use the following command : shell docker ps

You can use the docker logs command (replace mybunker and myautoconf with the name of your containers) : shell docker logs mybunker docker logs myautoconf

Here is the docker-compose equivalent (replace mybunker and myautoconf with the name of the services declared in the docker-compose.yml file) : shell docker-compose logs mybunker docker-compose logs myautoconf

List services

To list the services you can use the following command : shell docker service ls

You can use the docker service logs command (replace mybunker and myautoconf my with the name of your services) : shell docker service logs mybunker docker service logs myautoconf

List pods

To list the pods you can use the following command : shell kubectl get pods

You can use the kubectl logs command (replace mybunker and myautoconf my with the name of your pods) : shell kubectl logs mybunker kubectl logs myautoconf

The logs are located inside the /var/log/nginx directory. There is two files : shell cat /var/log/nginx/error.log cat /var/log/nginx/access.log

Permissions

Don't forget that BunkerWeb runs as an unprivileged user for obvious security reasons. Double-check the permissions of files and folders used by BunkerWeb especially if you use custom configurations (more info here). You will need to set at least RW rights on files and RWX on folders.

ModSecurity

The default BunkerWeb configuration of ModSecurity is to load the Core Rule Set in anomaly scoring mode with a paranoia level (PL) of 1 :

  • Each matched rule will increase an anomaly score (so many rules can match a single request)
  • PL1 include rules with fewer chances of false positives (but less security than PL4)
  • the default threshold for anomaly score is 5 for requests and 4 for responses

Let's take the following logs as an example of ModSecurity detection using default configuration (formatted for better readability) :

log 2022/04/26 12:01:10 [warn] 85#85: *11 ModSecurity: Warning. Matched "Operator `PmFromFile' with parameter `lfi-os-files.data' against variable `ARGS:id' (Value: `/etc/passwd' ) [file "/opt/bunkerweb/core/modsecurity/files/coreruleset/rules/REQUEST-930-APPLICATION-ATTACK-LFI.conf"] [line "78"] [id "930120"] [rev ""] [msg "OS File Access Attempt"] [data "Matched Data: etc/passwd found within ARGS:id: /etc/passwd"] [severity "2"] [ver "OWASP_CRS/3.3.2"] [maturity "0"] [accuracy "0"] [tag "application-multi"] [tag "language-multi"] [tag "platform-multi"] [tag "attack-lfi"] [tag "paranoia-level/1"] [tag "OWASP_CRS"] [tag "capec/1000/255/153/126"] [tag "PCI/6.5.4"] [hostname "172.17.0.2"] [uri "/"] [unique_id "165097447014.179282"] [ref "o1,10v9,11t:utf8toUnicode,t:urlDecodeUni,t:normalizePathWin,t:lowercase"], client: 172.17.0.1, server: localhost, request: "GET /?id=/etc/passwd HTTP/1.1", host: "localhost" 2022/04/26 12:01:10 [warn] 85#85: *11 ModSecurity: Warning. Matched "Operator `PmFromFile' with parameter `unix-shell.data' against variable `ARGS:id' (Value: `/etc/passwd' ) [file "/opt/bunkerweb/core/modsecurity/files/coreruleset/rules/REQUEST-932-APPLICATION-ATTACK-RCE.conf"] [line "480"] [id "932160"] [rev ""] [msg "Remote Command Execution: Unix Shell Code Found"] [data "Matched Data: etc/passwd found within ARGS:id: /etc/passwd"] [severity "2"] [ver "OWASP_CRS/3.3.2"] [maturity "0"] [accuracy "0"] [tag "application-multi"] [tag "language-shell"] [tag "platform-unix"] [tag "attack-rce"] [tag "paranoia-level/1"] [tag "OWASP_CRS"] [tag "capec/1000/152/248/88"] [tag "PCI/6.5.2"] [hostname "172.17.0.2"] [uri "/"] [unique_id "165097447014.179282"] [ref "o1,10v9,11t:urlDecodeUni,t:cmdLine,t:normalizePath,t:lowercase"], client: 172.17.0.1, server: localhost, request: "GET /?id=/etc/passwd HTTP/1.1", host: "localhost" 2022/04/26 12:01:10 [error] 85#85: *11 [client 172.17.0.1] ModSecurity: Access denied with code 403 (phase 2). Matched "Operator `Ge' with parameter `5' against variable `TX:ANOMALY_SCORE' (Value: `10' ) [file "/opt/bunkerweb/core/modsecurity/files/coreruleset/rules/REQUEST-949-BLOCKING-EVALUATION.conf"] [line "80"] [id "949110"] [rev ""] [msg "Inbound Anomaly Score Exceeded (Total Score: 10)"] [data ""] [severity "2"] [ver "OWASP_CRS/3.3.2"] [maturity "0"] [accuracy "0"] [tag "application-multi"] [tag "language-multi"] [tag "platform-multi"] [tag "attack-generic"] [hostname "172.17.0.2"] [uri "/"] [unique_id "165097447014.179282"] [ref ""], client: 172.17.0.1, server: localhost, request: "GET /?id=/etc/passwd HTTP/1.1", host: "localhost"

As we can see there are 3 different logs :

  1. Rule 930120 matched
  2. Rule 932160 matched
  3. Access denied (rule 949110)

One important thing to understand is that rule 949110 is not a "real" one : it's the one that will deny the request because the anomaly threshold is reached (which is 10 in this example). You should never remove the 949110 rule !

If it's a false-positive you should then focus on both 930120 and 932160 rules. ModSecurity and/or CRS tuning is out of the scope of this documentation but don't forget that you can apply custom configurations before and after the CRS is loaded (more info here).

Bad Behavior

A common false-positive case is that the client is banned because of the "bad behavior" feature which means that too many suspicious HTTP status codes were generated within a time period (more info here). You should start by reviewing the settings and edit them according to your web application(s) like removing a suspicious HTTP code, decreasing the count time, increasing the threshold, ...

IP unban

You can manually unban an IP which can be useful when doing some tests but it needs the setting USE_API set to yes (which is not the default) so you can contact the internal API of BunkerWeb (replace 1.2.3.4 with the IP address to unban) :

You can use the docker exec command (replace mybunker with the name of your container) : shell docker exec mybunker bwcli unban 1.2.3.4

Here is the docker-compose equivalent (replace mybunker with the name of the services declared in the docker-compose.yml file) : shell docker-compose exec mybunker bwcli unban 1.2.3.4

You can use the docker exec command (replace mya with the name of your container) : shell docker exec mybunker bwcli unban 1.2.3.4

Here is the docker-compose equivalent (replace mybunker with the name of the services declared in the docker-compose.yml file) : shell docker-compose exec mybunker bwcli unban 1.2.3.4

You can use the docker exec command (replace myautoconf with the name of your service) : shell docker exec $(docker ps -q -f name=myautoconf) bwcli unban 1.2.3.4

You can use the kubectl exec command (replace myautoconf with the name of your pod) : shell kubectl exec myautoconf bwcli unban 1.2.3.4

You can use the bwcli command : shell bwcli unban 1.2.3.4

Whitelisting

If you have bots that need to access your website, the recommended way to avoid any false positive is to whitelist it using the whitelisting feature. We don't recommend using the WHITELIST_URI* or WHITELIST_USER_AGENT* settings unless they are set to secret and unpredictable values. Common use cases are :

  • Healthcheck / status bot
  • Callback like IPN or webhook
  • Social media crawler