CIS Logo
tagline: Confidence in the Connected World

A Vulnerability in Apache Struts Could Allow for Remote Code Execution

MS-ISAC ADVISORY NUMBER:

2018-093

DATE(S) ISSUED:

08/22/2018

OVERVIEW:

A vulnerability has been discovered in Apache Struts, which could allow for remote code execution. Apache Struts is an open-source, MVC framework for creating Java web applications. Successfully exploiting this vulnerability could allow for remote code execution in the context of the affected application. Depending on the privileges associated with the application, an attacker could install programs; view, change, or delete data; or create new accounts with full user rights. Failed exploitation could result in a denial-of-service condition.

THREAT INTELLIGENCE:

Researchers at Tenable Security have discovered proof of concept exploit code has been made available on a GitHub repository. They also have observed active probing of sites for the existence of the remote code execution (RCE) vulnerability enumerated in CVE-2018-11776.

August 23 – UPDATED THREAT INTELLIGENCE
Researchers at Tenable Security have discovered proof of concept exploit code available on a GitHub repository for the remote code execution (RCE) vulnerability enumerated in CVE-2018-11776. They have also observed active probing of sites for this vulnerability. This vulnerability is exploitable on Apache Struts 2.3 - 2.3.34 or Struts 2.5 – 2.5.16.

August 28 - UPDATED THREAT INTELLIGENCE
A python exploit script for the vulnerability has been released on GitHub. Volexity reports that active scanning and exploitation attempts for the vulnerability have been observed in the wild. They have observed a threat attacker conducting widespread scanning and exploitation of the vulnerability in order to install the CNRig cryptocurrency miner. More information is available in the references.

SYSTEMS AFFECTED:

  • Apache Struts versions prior to 2.3.35
  • Apache Struts versions prior to 2.5.17

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 vulnerability has been discovered in Apache Struts, which could allow for remote code execution. Apache Struts is prone to a remote code-execution vulnerability (CVE-2018-11776). Specifically, this issue occurs when handling specially-crafted results with no namespace, or a URL tag without value and action set.

Successfully exploiting this vulnerability could allow for remote code execution in the context of the affected application. Depending on the privileges associated with the application, an attacker could install programs; view, change, or delete data; or create new accounts with full user rights. Failed exploitation could result in a denial-of-service condition.

RECOMMENDATIONS:

We recommend the following actions be taken:

  • Upgrade to the latest version of Apache Struts immediately, after appropriate testing.
  • Verify no unauthorized system modifications have occurred on system before applying patch.
  • Apply the principle of Least Privilege to all systems and services.
  • Remind users not to visit websites or follow links provided by unknown or untrusted sources.

REFERENCES:

Get Email Updates When Cyber Threats Like This Arise

Arrow Subscribe to Advisories

Protect Your Systems from Cyber Threats Like This

CIS Controls That Help Avoid This Issue Arrow CIS Control 3: Continuous Vulnerability Assessment and Remediation Arrow CIS Control 18: Application Software Security

Information Hub : Advisories


CONTROL: 1 --- ADVISORY CONTROL: 0
CONTROL: 2 --- ADVISORY CONTROL: 0

Pencil White paper 14 Mar 2019
CONTROL: 3 --- ADVISORY CONTROL: 0
CONTROL: 4 --- ADVISORY CONTROL: 0