Denial of service in Apache Tomcat

Published: 2020-06-27
Risk Medium
Patch available YES
Number of vulnerabilities 1
CVE-ID CVE-2020-11996
Exploitation vector Network
Public exploit Public exploit code for vulnerability #1 is available.
Vulnerable software
Apache Tomcat
Server applications / Web servers

Vendor Apache Foundation

Security Bulletin

This security bulletin contains one medium risk vulnerability.

1) Resource management error

EUVDB-ID: #VU29333

Risk: Medium


CVE-ID: CVE-2020-11996

CWE-ID: CWE-399 - Resource Management Errors

Exploit availability: Yes


The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to improper management of internal resources with the application when processing HTTP/2 requests. A remote attacker can send specially crafted sequence of HTTP/2 requests to the affected server and trigger high CPU load for several seconds. A large number of such requests causes denial of service.


Install updates from vendor's website.

Vulnerable software versions

Apache Tomcat: 10.0.0-M1 -, 9.0.0 - 9.0.35, 8.5.0 - 8.5.55

CPE2.3 External links

Q & A

Can this vulnerability be exploited remotely?

How the attacker can exploit this vulnerability?

Is there known malware, which exploits this vulnerability?