A Vulnerability in 7-Zip Could Allow for Arbitrary Code Execution

ITS Advisory Number: 
2018-050
Date(s) Issued: 
Wednesday, May 2, 2018
Subject: 
A Vulnerability in 7-Zip Could Allow for Arbitrary Code Execution
Overview: 

A vulnerability has been discovered in 7-Zip, which could allow for arbitrary code execution. 7-Zip is a free and open-source file archiver. Successful exploitation of this vulnerability could allow for arbitrary code execution. Depending on the privileges associated with the user, an attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. Users whose accounts are configured to have fewer user rights on the system could be less impacted than those who operate with administrative user rights.

Systems Affected: 
  • 7-Zip versions prior to 18.05
RISK
GOVERNMENT
Large and medium government entities: 
High
Small government entities: 
High
BUSINESS
Large and medium business entities: 
High
Small business entities: 
High
Home Users: 
High
Description: 

A vulnerability has been discovered in 7-Zip, which could allow for arbitrary code execution. The NArchive::NRar::CHandler::Extract method in CPP/7zip/Archive/Rar/RarHandler.cpp performs decoding of archive data using a largely uninitialized state. This state together with a lack of address space layout randomization (ASLR) on the main executables (7zFM.exe, 7zG.exe, 7z.exe) can cause memory corruptions that lead to arbitrary code execution. (CVE-2018-10115)

Successful exploitation of this vulnerability could allow for arbitrary code execution. Depending on the privileges associated with the user, an attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. Users whose accounts are configured to have fewer user rights on the system could be less impacted than those who operate with administrative user rights.

Actions: 
  • After appropriate testing, immediately apply updates provided by 7-Zip to vulnerable systems.
  • Run all software as a non-privileged user (one without administrative privileges) to diminish the effects of a successful attack.
  • Apply the Principle of Least Privilege to all systems and services.