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2.1.04 scanner stalling on pretty much every test

Ian Nov 05, 2019 01:58PM UTC

Hello, I've been trying to use the newer burp but so far I'm having great trouble making it actually perform its job effectively due to scans rarely finishing and having to frequently be "unstuck".

The pattern at the moment is for a scan to be started with some settings setup up to try and prevent lock-ups, at the moment the "handling application errors during audit" is set to skip remaining checks if there's 1 failure, and skip remaining insertion points if 1 failure is seen. It's set to pause a task only if 1,000 consecutive audit items fail. This is solely to try to prevent these dreadful lock-ups.

In Project Options I've dropped all the timeouts down to about 5 seconds, again to try to prevent lock-ups.

What essentially happens is that after a while, the scanner stalls. I go into audit items and find that 20 or so (however many parallel requests are permitted) items are marked as "Scanning" but nothing is happening. To get things going again I either have to change scanning resource to one that handles more simultaneous requests, or I have to select the stalled audit items, cancel them, then audit again.

As a result of the constant scanner stalls, active scans rarely get past phase 1 on anything but the smallest apps. I succeeded on getting a login form through all scanning phases recently and regarded this as a bit of a victory. Just a simple login form, that's all it could do without breaking.

This fixes things temporarily but it then just stalls again. I've done about 4 tests using the 2.x branch of burp but will be ripping it out and going back to 1.x for the next test until I get the OK from some of my colleagues who are persisting with it at the moment, the rest have gone back to 1.x for the same reason -- stalling scanners.


Ian Nov 05, 2019 03:17PM UTC
I suspect this is a plugin as things have progressed much better since I unloaded all the plugins, is there any rapid way to find out which one is causing trouble? I tried looking at the debug tab but nothing much in there and there's no significant shell output.

Liam Tai-Hogan Nov 05, 2019 04:14PM UTC Support Center agent

Do you have performance feedback enabled (User options > Misc > Performance feedback)? If so, could you provide us with your diagnostics (Help > Diagnostics)? We can check for excpetions related to specific extensions.

Failing that, the best way to locate the extension causing the issue would be to enable them one at a time.


Ian Nov 05, 2019 04:45PM UTC
I've disabled all the plugins bar one, does this affect the usefulness of the debug information?

Mike Eaton Nov 06, 2019 09:31AM UTC Support Center agent

Hi Ian

This won’t affect the content of the debug information, if you can provide us with your Debug ID we can use that to locate the diagnostic information your Burp Suite installation is sending back to us from your testing.

If you enable your extensions one at a time, and run a scan on each enabled extension, it will allow you to identify which extension is causing issues when scanning.


Ian Nov 12, 2019 10:38AM UTC
OK it's stalled again, I've unloaded all the extensions while it's stalled but it's not unstuck itself (unloading a few extensions unstuck it previously, presumably by coincidence). Here's the info from debug:

awt.toolkit sun.awt.X11.XToolkit
exe4j.moduleName /home/user1/Library/Apps/BurpSuite/Current/BurpSuitePro/BurpSuitePro
file.encoding UTF-8
file.separator /
i4j.vpt true
i4jv 0
install4j.appDir /home/user1/Library/Apps/BurpSuite/Current/BurpSuitePro/
install4j.exeDir /home/user1/Library/Apps/BurpSuite/Current/BurpSuitePro/
install4j.jvmDir /home/user1/Library/Apps/BurpSuite/Current/BurpSuitePro/jre
install4j.launcherId 70
install4j.swt false
java.awt.graphicsenv sun.awt.X11GraphicsEnvironment
java.awt.printerjob sun.print.PSPrinterJob
java.class.path /home/user1/Library/Apps/BurpSuite/Current/BurpSuitePro/.install4j/i4jruntime.jar:/home/user1/Library/Apps/BurpSuite/Current/BurpSuitePro/burpsuite_pro.jar
java.class.version 55.0
java.home /home/user1/Library/Apps/BurpSuite/Current/BurpSuitePro/jre
java.io.tmpdir /tmp
java.library.path /usr/java/packages/lib:/usr/lib64:/lib64:/lib:/usr/lib
java.runtime.name OpenJDK Runtime Environment
java.runtime.version 11.0.2+9
java.specification.name Java Platform API Specification
java.specification.vendor Oracle Corporation
java.specification.version 11
java.vendor Oracle Corporation
java.vendor.url http://java.oracle.com/
java.vendor.url.bug http://bugreport.java.com/bugreport/
java.vendor.version 18.9
java.version 11.0.2
java.version.date 2019-01-15
java.vm.compressedOopsMode Zero based
java.vm.info mixed mode
java.vm.name OpenJDK 64-Bit Server VM
java.vm.specification.name Java Virtual Machine Specification
java.vm.specification.vendor Oracle Corporation
java.vm.specification.version 11
java.vm.vendor Oracle Corporation
java.vm.version 11.0.2+9
jdk.debug release
jdk.tls.allowUnsafeServerCertChange true
jdk.tls.server.protocols TLSv1,TLSv1.1,TLSv1.2
os.arch amd64
os.name Linux
os.version 5.3.0-kali1-amd64
path.separator :
python.cachedir.skip true
python.console.encoding UTF-8
sun.arch.data.model 64
sun.awt.enableExtraMouseButtons true
sun.boot.library.path /home/user1/Library/Apps/BurpSuite/Current/BurpSuitePro/jre/lib
sun.cpu.endian little
sun.cpu.isalist
sun.font.fontmanager sun.awt.X11FontManager
sun.io.unicode.encoding UnicodeLittle
sun.java.command com.install4j.runtime.launcher.UnixLauncher launch ccf7dac9 0 0 burp.StartBurp
sun.java.launcher SUN_STANDARD
sun.jnu.encoding UTF-8
sun.management.compiler HotSpot 64-Bit Tiered Compilers
sun.nio.ch.bugLevel
sun.os.patch.level unknown
user.country GB
user.dir /home/user1/Library/Apps/BurpSuite/Current/BurpSuitePro
user.home /home/user1
user.language en
user.name user1
user.timezone Europe/London

Burp Version 2.1.04
Burp Browser Version 0.144
Burp Browser binaries /home/user1/Library/Apps/BurpSuite/Current/BurpSuitePro/burpbrowser/0.144
Code source /home/user1/Library/Apps/BurpSuite/Current/BurpSuitePro/burpsuite_pro.jar
Debug ID pfhvwl9vahzty6jkmw9j:mps6
JAR type Installer

PATH /home/user1/.bin:/usr/local/sbin:/usr/sbin:/sbin:/usr/local/bin:/usr/bin:/bin:/usr/local/games:/usr/games
XAUTHORITY /home/user1/.Xauthority
XDG_DATA_DIRS /usr/share:/usr/share:/usr/local/share
KDE_SESSION_UID 1000
LANG en_GB.UTF-8
DBUS_SESSION_BUS_ADDRESS unix:path=/run/user/1000/bus
XDG_SEAT_PATH /org/freedesktop/DisplayManager/Seat0
XDG_SESSION_ID 7
XDG_SESSION_TYPE x11
XDG_CURRENT_DESKTOP KDE
DISPLAY :0
QT_AUTO_SCREEN_SCALE_FACTOR 0
SSH_AGENT_PID 841
SESSION_MANAGER local/kali2019:@/tmp/.ICE-unix/908,unix/kali2019:/tmp/.ICE-unix/908
LOGNAME user1
PWD /home/user1/Library/Apps/BurpSuite/Current/BurpSuitePro
PAM_KWALLET5_LOGIN /run/user/1000/kwallet5.socket
XCURSOR_THEME breeze_cursors
XDG_SESSION_CLASS user
LANGUAGE en_GB:en
KDE_SESSION_VERSION 5
SHELL /bin/bash
GPG_AGENT_INFO /run/user/1000/gnupg/S.gpg-agent:0:1
DESKTOP_SESSION /usr/share/xsessions/plasma
OLDPWD /home/user1/Library/Apps/BurpSuite/Current/BurpSuitePro/jre
USER user1
DESKTOP_STARTUP_ID kali2019;1573550513;790156;924_TIME593264
KDE_FULL_SESSION true
QT_ACCESSIBILITY 1
SSH_AUTH_SOCK /tmp/ssh-n16h6psQQngp/agent.800
XDG_SEAT seat0
GS_LIB /home/user1/.fonts
XDG_SESSION_PATH /org/freedesktop/DisplayManager/Session1
XDG_VTNR 7
XDG_SESSION_DESKTOP KDE
XDG_RUNTIME_DIR /run/user/1000
HOME /home/user1
SHLVL 0

Wsdler Extension type: Java
Site Map Fetcher Extension type: Python
Custom Extension type: Java
Content Type Converter Extension type: Java
Custom Logger Extension type: Java
JSON Decoder Extension type: Python
.NET Beautifier Extension type: Java
WSDL Wizard Extension type: Python
CMS Scanner Extension type: Java
Cloud Storage Tester Extension type: Python
J2EEScan Extension type: Java
Additional Scanner Checks Extension type: Python
Active Scan++ Extension type: Python
Additional CSRF Checks Extension type: Python
AuthMatrix Extension type: Python
Autorize Extension type: Python
Backslash Powered Scanner Extension type: Java
Bypass WAF Extension type: Java
CO2 Extension type: Java
Error Message Checks Extension type: Java
Freddy, Deserialization Bug Finder Extension type: Java
HTML5 Auditor Extension type: Java
HTTPoxy Scanner Extension type: Java
Headers Analyzer Extension type: Python
JSON Beautifier Extension type: Java
Java Deserialization Scanner Extension type: Java
Logger++ Extension type: Java
Retire.js Extension type: Java
SSL Scanner Extension type: Python
Session Auth Extension type: Python
Software Version Reporter Extension type: Java
Software Vulnerability Scanner Extension type: Java
WordPress Scanner Extension type: Python

Total memory 641,728,512
Max memory 3,110,076,416
Free memory 167,549,096
Number of processors 3


Debug ID is: pfhvwl9vahzty6jkmw9j:mps6

Michelle Gillian Nov 12, 2019 03:52PM UTC Support Center agent

When it stalled this last time, was ‘Submit anonymous feedback about Burp’s Performance’ enabled (User options > Misc > Performance feedback)? The last data I can find from your installation is dated 7th November.

Also, can you try upgrading to the latest version 2.1.05 and starting a new scan with no extensions enabled, just to confirm that we see no errors at that point? If we just disable the extensions after it has failed it won’t necessarily point us at the cause of the problem.


Ian Nov 12, 2019 04:09PM UTC
Ah at the moment I'm on a site where the testing machine is not connected to the internet, that's not going to help much is it ;-) If I connect it to the net then will it upload the relevant data, or will I need to make it stall again when it's got an internet connection?

I'll detach the machine from the test network now and plug it into the net and do the upgrade, that might upload the performance data.

I'll try to do a scan tomorrow with no extensions, it's tricky as the stall isn't that predictable.

Ian Nov 12, 2019 04:35PM UTC
OK updated, I'll try it again tomorrow. Hopefully the performance data should have uploaded by now.

Ian Nov 13, 2019 11:13AM UTC
Sorry but it's stalling even when no plugins are loaded. I've got limited time to deal with this as I am on paying work, I'll keep playing with it today but tomorrow I'll be going back to Burp Suite 1.7, I can't use this.

Liam Tai-Hogan Nov 13, 2019 03:56PM UTC Support Center agent

Ian, thanks for trying that for us. Unfortunately, we still haven’t seen any debug information.

Can I ask, what number do you have set for “Pause the task if * consecutive items fail”?

Have you tried using Burp’s Resource Pool settings to throttle your scanning?

- https://portswigger.net/blog/burp-2-0-how-do-i-throttle-requests


Ian Nov 13, 2019 04:32PM UTC
It's got debugging turned on, it was updated yesterday, and it's been connected to both the client network and the internet all day, and user options->misc->Performance Feedback has been on for the last 3 days.

I'm on a fast internal network with a large app to test, so throttling shouldn't be needed, in fact I've created a new resource pool with 25 simultaneous requests. I've tended to do this to get scanning going again after it's stalled -- when it stalls, creating a new resource pool with more simultaneous requests than the last one had was one of the ways I'd get it unstalled.

As for the value of "pause the task", I've varied that through trying to get to the bottom of this but I don't have a definitive list of what I set it to and what happened. I've never noticed any difference even when I set it to quite a high number (I think I had it up to 1000 at one point). I've also dropped timeouts down to 20 seconds (who waits 5 minutes for a DNS request after all?) as this is a fast internal app. I also altered the two "skip remaining checks" to various values to try and stop it from grinding to a halt.

I suppose the best thing to do right now is to try and figure out why the debug information isn't uploading. What do we need to do this.

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