#VU56634 Infinite loop in Apache Tomcat

Published: 2021-09-15

Vulnerability identifier: #VU56634

Vulnerability risk: Medium


CVE-ID: CVE-2021-41079


Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Apache Tomcat
Server applications / Web servers

Vendor: Apache Foundation


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

The vulnerability exists due to infinite loop when processing certain TLS packets. A remote attacker can send a specially crafted packet to the application, consume all available system resources and cause denial of service conditions.

Successful exploitation of vulnerability requires that Apache Tomcat is configured to use NIO+OpenSSL or NIO2+OpenSSL for TLS.

Install updates from vendor's website.

Vulnerable software versions

Apache Tomcat: 10.0.0 - 10.0.2, 9.0.0 - 9.0.43, 8.5.0 - 8.5.63


External links

Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?

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