QID 730142

Date Published: 2021-07-19

QID 730142: 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

QID Detection Logic (Unauthenticated):
The QID checks for vulnerable version by sending a GET /QUALYS730142 HTTP/1.0 request which helps in retrieving the installed version of Apache Tomcat in the banner of the response.

Successful exploitation of the vulnerability can allow an attacker to trigger non-blocking I/O errors, e.g. by dropping a connection, thereby creating the possibility of triggering a DoS. Applications that do not use non-blocking I/O are not exposed to this vulnerability.

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.

Vendor References

Apache Tomcat 10.0.5 - tomcat.apache.org/security-10.html#Fixed_in_Apache_Tomcat_10.0.5

CVEs related to QID 730142

CVE-2021-30639 |

Software Advisories

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

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