A Vulnerability in GNU C Library Could Allow for Arbitrary Code Execution

ITS Advisory Number: 
2018-017
Date(s) Issued: 
Tuesday, February 6, 2018
Subject: 
A Vulnerability in GNU C Library Could Allow for Arbitrary Code Execution
Overview: 

A vulnerability has been discovered in the GNU C Library (glibc), which could allow for arbitrary code execution. This library is required in all modern distributions of Linux as it defines the system calls and other basic facilities used in the Linux kernel. Successful exploitation of this vulnerability could result in an attacker gaining the same privileges as the exploited application. Depending on the privileges associated with the application, an attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. If this application has been configured to have fewer user rights on the system, exploitation of this vulnerability could have less impact than if it was configured with administrative rights. Failed exploit attempts could lead to a denial of service condition for the affected application.   

 

THREAT INTELLIGENCE:

There are currently no reports of this vulnerability being exploited in the wild. However, a proof of concept exploit has been publicly released.

Systems Affected: 

GNU C Library versions 2.26 and prior

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 the GNU C Library, which could allow for arbitrary code execution. Specifically, this is an integer overflow vulnerability due to internal memalign() and malloc() functions in glibc failing to properly report allocation errors. This vulnerability can be exploited when the system processes maliciously crafted data.

Successful exploitation of this vulnerability could result in an attacker gaining the same privileges as the exploited application. Depending on the privileges associated with the application, an attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. If this application has been configured to have fewer user rights on the system, exploitation of this vulnerability could have less impact than if it was configured with administrative rights. Failed exploit attempts could lead to a denial of service condition for the affected application.

 

Actions: 
  • After appropriate testing, immediately install the apply patches provided by the affected *nix distribution to the vulnerable systems.

  • Run all software as a non-privileged user (one without administrative privileges) to diminish the effects of a successful attack.