Buffer overflow steps / explanation from other sources

from http://netsec.ws/?p=180

Step 1. Typical memory layout.

Step 2. Attackers input exceeds user buffer. Test it manually or create pattern for specific size using pattern_create.rb or one line python script to test with alphabets A, b & C

Step 3a. Correctly handled – Attackers input get truncated to the buffer and can’t overwrite anything.

Step 3b. Incorrectly Handled – Attackers input overwrites the buffer and EIP, causing it to jump to an invalid memory address and crash: & create pattern using pattern_offeset to find offset

Step 4. Attacker creates tailored input : create shellcode may be using msfvenom

Step 5. Attackers input overwrites EIP with their own address pointing to the start of their shellcode: script using buffer, nops and return address

Comments

VM 13 : Basic Pentest 1 csec

Notes: Walkthru: 1. https://medium.com/@evire/basic-pentesting-1-7251fb3e3f9e [ w/metasploi t using Wordpress t] 2. https://prasannakumar.in/infosec/vulnhub-basic-pentesting-1-writeup/ [ w/metasploit using ftp ] 3. https://www.ceos3c.com/hacking/basic-pentesting-1-walkthrough/ [ by uploading php-reverse-shell in wordpress ] 4. http://k3ramas.blogspot.com/2018/02/basic-pentesting-1-walkthrough.html [ access wordpress config file to get pwd and access the DB ] 5. https://cowsayroot.com/walkthrough-basic-pentesting-1/ [ Wpscan, ftp metasploit vulnerability, phpbash ] 6. http://www.hackingarticles.in/hack-the-basic-penetration-vm-boot2root-challenge/ [use msfvenom to create to create php shell to be uploaded in Wordpress ] 7. https://d7x.promiselabs.net/2018/01/30/ctf-basic-pentesting-a-guide-for-beginners/ [adding command using using PHP] Notes: Ports - 21...ProFTPD 1.3.3c - 22 openSSH 7.2p2 ubuntu ...

VM: pWnOS 2.0

Walkthru A. http://defsecurityjam.blogspot.co.uk/2015/07/pwnos-version-2-walkthrough.html [reading source page, Simple PHP Blog Perl exploit, Python revershell using oneliner, looking around ] b. https://blog.g0tmi1k.com/2012/09/pwnos-2-php-web-application/ [metasploit using PHP Blog exploit] c. http://netsec.ws/?p=430 [burpsuite, sql porxy] d. https://blog.g0tmi1k.com/2012/09/pwnos-2-sql-injection/ [sql injection, union. Very good explanation of the process of what is being done. Didnt try cmds] e. https://www.youtube.com/watch?v=ytzZfI27ueU [sql injection, sqlmap read file and upload reverse shell using sqlmap] f. https://ub3rsec.github.io/pages/2016/pwnosv2-sqli.html [sql injection, union using burp Very good . It list all email field that we are passing and modifying thru burp suite/proxy/intercept. One could enter those union statements in the email field but in this case, the field truncates and remove the later part of union statment which is why we...

38 VM : d0not5top: 1.2

https://www.vulnhub.com/?q=D0Not5top&sort=date-des&type=vm Walkthru: A. https://github.com/Hamza-Megahed/CTFs/blob/master/d0not5top/README [ burp proxy, adding hostnames to /etc/host shows following but not working for me. Not showing localhost stuff, $ dirb http://172.16.34.163/control/ -X .txt,.php,.html + http://172.16.34.163/control/hosts.txt 127.0.0.1 localhost 127.0.0.1 D0Not5top.ctf #127.0.0.1 MadBroAdN1n.ctf ## AD105 M0F05] B. https://adaywithtape.blogspot.com/2017/04/vulnhub-d0not5top-writeup.html [use nc cmd to get the flag and echo cmd to decode the flag, wfuzz, virtualhost, partially binary string, google language translate, curl -header host request, additional domains, OWSAP ZAP, exiftool, HD, hash64,] wfuzz -c -w /usr/share/seclists/Discovery/Web_Content/common.txt --hc 404 192.168.56.102/FUZZ Changing the syntax just a tad to only show html 200...

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