CVE-2021-41079

Name: CVE-2021-41079
Creator: NVD / NIST
Published: 2021-09-16T15:15:07.69+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 6.69%

Last modified Jun 17, 2026

CVE-2021-41079 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. Apache Tomcat 8.5.0 to 8.5.63, 9.0.0-M1 to 9.0.43 and 10.0.0-M1 to 10.0.2 did not properly validate incoming TLS packets. When Tomcat was configured to use NIO+OpenSSL or NIO2+OpenSSL for TLS, a specially crafted packet could be used to trigger an infinite loop resulting in a denial of service.. EPSS estimates a 6.69% chance of exploitation in the next 30 days.

Description

Apache Tomcat 8.5.0 to 8.5.63, 9.0.0-M1 to 9.0.43 and 10.0.0-M1 to 10.0.2 did not properly validate incoming TLS packets. When Tomcat was configured to use NIO+OpenSSL or NIO2+OpenSSL for TLS, a specially crafted packet could be used to trigger an infinite loop resulting in a denial of service.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

6.69%

93.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Apache	Tomcat	>= 8.5.0, < 8.5.64
Apache	Tomcat	>= 9.0.0, < 9.0.44
Apache	Tomcat	>= 10.0.0, <= 10.0.2
Debian	Debian Linux	9.0
Debian	Debian Linux	10.0
Debian	Debian Linux	11.0
Netapp	Management Services For Element Software And Netapp Hci	All versions

References

https://lists.apache.org/thread.html/r6b6b674e3f168dd010e67dbe6848b866e2acf26371452fdae313b98a%40%3Cusers.tomcat.apache.org%3E
https://lists.apache.org/thread.html/rb4de81ac647043541a32881099aa6eb5a23f1b7fd116f713f8ab9dbe%40%3Cdev.tomcat.apache.org%3E
https://lists.apache.org/thread.html/rccdef0349fdf4fb73a4e4403095446d7fe6264e0a58e2df5c6799434%40%3Cannounce.tomcat.apache.org%3EMailing List, Vendor Advisory
https://lists.debian.org/debian-lts-announce/2021/09/msg00012.htmlMailing List, Third Party Advisory
https://security.netapp.com/advisory/ntap-20211008-0005/Third Party Advisory
https://www.debian.org/security/2021/dsa-4986Third Party Advisory
https://lists.apache.org/thread.html/r6b6b674e3f168dd010e67dbe6848b866e2acf26371452fdae313b98a%40%3Cusers.tomcat.apache.org%3E
https://lists.apache.org/thread.html/rb4de81ac647043541a32881099aa6eb5a23f1b7fd116f713f8ab9dbe%40%3Cdev.tomcat.apache.org%3E
https://lists.apache.org/thread.html/rccdef0349fdf4fb73a4e4403095446d7fe6264e0a58e2df5c6799434%40%3Cannounce.tomcat.apache.org%3EMailing List, Vendor Advisory
https://lists.debian.org/debian-lts-announce/2021/09/msg00012.htmlMailing List, Third Party Advisory
https://security.netapp.com/advisory/ntap-20211008-0005/Third Party Advisory
https://www.debian.org/security/2021/dsa-4986Third Party Advisory

Timeline

Published: Sep 16, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-41079?

How severe is CVE-2021-41079?

CVE-2021-41079 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 6.69% probability of exploitation in the next 30 days.

How do I fix CVE-2021-41079?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-41079?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST