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

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

MS-ISAC ADVISORY NUMBER:

2016-021

DATE(S) ISSUED:

01/29/2016

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. 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 publically released.

SYSTEMS AFFECTED:

  • GNU glibc prior to version 2.23

RISK:

Government:
  • Large and medium government entities: HIGH
  • Small government entities: HIGH
Businesses:
  • Large and medium business entities: HIGH
  • Small business entities: HIGH
Home Users:
LOW

TECHNICAL SUMMARY:

A stack-based buffer overflow vulnerability has been discovered in GNU libc that could allow remote code execution on the affected device. Specifically, this vulnerability affects the 'catopen()' function in libc where it fails to properly bound-check user-supplied data. This vulnerability can be exploited when the system processes maliciously crafted data. (CVE-2015-8779)

An attacker can exploit this vulnerability to execute arbitrary code in the context of the affected application. 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. Failed exploit attempts could lead to a denial of service condition for the affected application.

RECOMENDATIONS:

We recommend the following actions be taken:

Apply appropriate patches provided by the affected *nix distribution to the vulnerable systems immediately after appropriate testing.

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

REFERENCES:

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