Flaw in Apache Tomcat forces server to perform DoS attacks against itself & the network

Specialists from a cyber security consulting firm report finding of a medium severity vulnerability in Apache Tomcat, the servlet container developed under the Apache Software Foundation’s Jakarta project. According to the report, successful exploitation of this vulnerability would allow the deployment of denial of service (DoS) attacks against the affected deployment.

Below is a brief description of the reported flaw, in addition to their respective score and identification key according to the Common Vulnerability Scoring System (CVSS).

CVE-2020-11996: Inadequate management of internal resources in the application when processing HTTP/2 requests would allow remote hackers to perform denial of service (DoS) attacks. Threat actors could send a sequence of HTTP/2 requests specially designed to trigger high CPU consumption for several seconds, eventually generating the DoS condition.  

As cyber security consulting firm experts mention, the vulnerability received a score of 6.5/10 on the CVSS scale, so it is considered an average severity error.

The following is a list of the apache Tomcat versions affected by this security flaw: 8.5.0, 8.5.1, 8.5.2, 8.5.3, 8.5.4, 8.5.5, 8.5.6, 8.5.7, 8.5.8, 8.5.9, 8.5.10, 8.5.11, 8.5.12, 8.5.13, 8.5.14, 8.5.15, 8.5.16, 8.5.17, 8.5.18, 8.5.19, 8.5.20, 8.5.21, 8.5.22, 8.5.23, 8.5.24, 8.5.25, 8.5.26, 8.5.27, 8.5.28, 8.5.29, 8.5.30, 8.5.31, 8.5.32, 8.5.33, 8.5.34, 8.5.35, 8.5.36, 8.5.37, 8.5.38, 8.5.39, 8.5.40, 8.5.41, 8.5.42, 8.5.43, 8.5.44, 8.5.45, 8.5.46, 8.5.47, 8.5.48, 8.5.49, 8.5.50, 8.5.51, 8.5.52, 8.5.53, 8.5.54, 8.5.55, 9.0.0, 9.0.0-M1, 9.0.0-M2, 9.0.0-M3, 9.0.0-M4, 9.0.0-M5, 9.0.0-M6, 9.0.0-M7, 9.0.0-M8, 9.0.0-M9, 9.0.0-M10, 9.0.0-M11, 9.0.0-M12, 9.0.0-M13, 9.0.0-M14, 9.0.0-M15, 9.0.0-M16, 9.0.0-M17, 9.0.0-M18, 9.0.0-M19, 9.0.0-M20, 9.0.0-M21, 9.0.0-M22, 9.0.0-M23, 9.0.0-M24, 9.0.0-M25, 9.0.0-M26, 9.0.0-M27, 9.0.1, 9.0.2, 9.0.3, 9.0.4, 9.0.5, 9.0.6, 9.0.7, 9.0.8, 9.0.9, 9.0.10, 9.0.11, 9.0.12, 9.0.13, 9.0.14, 9.0.15, 9.0.16, 9.0.17, 9.0.18, 9.0.19, 9.0.20, 9.0.21, 9.0.22, 9.0.23, 9.0.24, 9.0.25, 9.0.26, 9.0.27, 9.0.28, 9.0.29, 9.0.30, 9.0.31, 9.0.32, 9.0.33, 9.0.34, 9.0.35, 10.0.0-M1, 10.0.0-M2, 10.0.0-M3, 10.0.0-M4, 10.0.0-M5, 10.0.0.0-M1.

Although cyber security consulting experts demonstrated that the flaw could be exploited remotely by unauthenticated threat actors over the Internet, no cases of active exploitation have been detected so far. Researchers also do not know if there are any malware variants associated with exploiting this flaw.

The team behind Apache Tomcat recognized the flaw and began working on a fix immediately after receiving the report. Updates are now available, so affected deployment administrators should only verify their installation.

For further reports on vulnerabilities, exploits, malware variants and computer security risks, it is recommended to enter the website of the International Institute of Cyber Security (IICS), as well as the official platforms of technology companies.