Burp Suite User Forum

Private Burp Collaborator Server: Unexpected Exceptions - Problem handling DNS requests

Thorsten | Last updated: May 10, 2020 01:51PM UTC

Hello, I am running a private Burp Collaborator Server (current version of Burp) on an AWS EC2 instance. It's working and all health check tests were successful, but I found a lot of error messages in the log: -------------------------------------------------------------------------------- 2020-05-10 12:35:10.690 : Problem handling DNS request burp.ei3: Invalid label character set in 6E73312E74686F6B752E78797A at burp.d7x.a(Unknown Source) at burp.d7x.<init>(Unknown Source) at burp.cox.f(Unknown Source) at burp.cox.<init>(Unknown Source) at burp.bzv.run(Unknown Source) at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515) at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) at java.base/java.lang.Thread.run(Thread.java:834) 2020-05-10 12:35:10.690 : Raw dns request = 1574001000010000000000010D6E73312E74686F6B752E78797A0574686F6B750378797A000001000100002905C0000080000000 Exception report: Category: UNEXPECTED Detail: burp.ei3: Invalid label character set in 6E73312E74686F6B752E78797A at burp.d7x.a(Unknown Source) at burp.d7x.<init>(Unknown Source) at burp.cox.f(Unknown Source) at burp.cox.<init>(Unknown Source) at burp.bzv.run(Unknown Source) at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515) at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) at java.base/java.lang.Thread.run(Thread.java:834) -------------------------------------------------------------------------------- The value of the "Raw dns request" is different in every error message, the rest always remains the same. Is there anything I can do to solve this? Thanks!

Michelle, PortSwigger Agent | Last updated: May 11, 2020 03:48PM UTC

You can see this message in the logs if people are hitting the collaborator with invalid DNS queries. Please let us know if you need any further assistance.

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