QID 150444

Date Published: 2022-01-11

QID 150444: Apache Tomcat Denial of Service Vulnerability (CVE-2021-30639)

Apache Tomcat is an open source web server and servlet container developed by the Apache Software Foundation.

A vulnerability in Apache Tomcat allows an attacker to remotely trigger a denial of service. An error introduced as part of a change to improve error handling during non-blocking I/O meant that the error flag associated with the Request object was not reset between requests.

Affected Versions:
Apache Tomcat 10.0.3 to 10.0.4
Apache Tomcat 9.0.44
Apache Tomcat 8.5.64

An attacker were able to trigger non-blocking I/O errors, e.g. by dropping a connection, thereby creating the possibility of triggering a DoS.

  • CVSS V3 rated as High - 7.5 severity.
  • CVSS V2 rated as Medium - 5 severity.
  • Solution
    Upgrade to the Apache Tomcat 10.0.5, 9.0.45, 8.5.65 versions or to the latest version of Apache Tomcat. Please refer to Apache Tomcat Security Advisory.

    CVEs related to QID 150444

    Software Advisories
    Advisory ID Software Component Link
    Apache_Tomcat_10.0.5 URL Logo tomcat.apache.org/security-10.html#Fixed_in_Apache_Tomcat_10.0.5