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A Vulnerability in Apache Tomcat Could Allow for Arbitrary File Reading (CVE-2020-1938)

MS-ISAC ADVISORY NUMBER:

2020-028

DATE(S) ISSUED:

03/02/2020

OVERVIEW:

A vulnerability has been discovered in Apache Tomcat, which could allow for reading of arbitrary files on the affected system. Apache Tomcat is an open-source web server that supports running Java code. Successful exploitation of the vulnerability could allow an attacker to read arbitrary files on the affected server. 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. If this application has been configured to have fewer user rights on the system, exploitation of the most severe of these vulnerabilities could have less impact than if it was configured with administrative rights.

THREAT INTELLIGENCE:

Proof-of-concept code has been released to GitHub by multiple security researchers.

SYSTEMS AFFECTED:

  • Apache Tomcat 9.x versions less than 9.0.31
  • Apache Tomcat 8.x versions less than 8.5.51
  • Apache Tomcat 7.x versions less than 7.0.100
  • Apache Tomcat 6.x versions (End of life, not patched)

RISK:

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

TECHNICAL SUMMARY:

A vulnerability has been discovered in Apache Tomcat, which could allow for reading of arbitrary files on the affected system. The vulnerability exists in the AJP protocol, which is by default exposed over TCP port 8009 and enabled. The vulnerability can be exploited by an attacker who can communicate with the affected AJP protocol service. If the server is running a web application that allows for file uploads, a remote file inclusion vulnerability becomes exploitable, that could allow for remote code execution. Successful exploitation of the vulnerability could allow an attacker to read arbitrary files on the affected server. 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. If this application has been configured to have fewer user rights on the system, exploitation of the most severe of these vulnerabilities could have less impact than if it was configured with administrative rights.

RECOMMENDATIONS:

We recommend the following actions be taken:

  • Apply the patches provided by Apache after appropriate testing.
  • If the AJP service is not required, disable it on the host.
  • If the AJP service does not need to be publicly accessible, ensure that access is filtered.
  • 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.

REFERENCES:

Information Hub : Advisories


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