
MAL-009: Insecure Chaining of Flags T and TT in Zip for Linux
In Zip for Linux, the “-TT” flag can be used to run arbitrary system commands. Due to the dangerous nature of this flag, it must always be used at the same time as the “-T” flag. By using a flag chaining attack, attackers that should only be able to insert just one flag in a zip command can insert both the “-T” and “-TT” flags and potentially execute malicious code.
More details and the exploitation process can be found in this PDF.
Example of potentially vulnerable application can be found in this python code.
This case study came to mind after exploiting CVE-2020-8248: Privilege Escalation via Zip Wildcard Exploit in Pulse Secure VPN Linux Client as I was curious if the command execution via Zip could be achived with just 1 file instead of 2.
Bug ticket concerning this vulnerability opened on bugs.launchpad.net on 18-Feb-2021
Other examples of Zip for Linux Flag Chaining leading to RCE: