Apache Tomcat DoS with unexpected TLS packet

MITRE NVD CVE.ORG JSON API Print: PDF PDF

Summary

CVECVE-2021-41079
StatePUBLISHED
Assignerapache
Source PriorityCVE Program / NVD first with legacy fallback
Published2021-09-16 15:15:07 UTC
Updated2026-10-08 22:17:12 UTC
DescriptionApache 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.

Risk And Classification

Primary CVSS: v3.1 7.5 HIGH from [email protected]

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

Problem Types: CWE-20 | CWE-835 | CWE-20 CWE-20 Improper Input Validation

VersionSourceTypeScoreSeverityVector
3.1[email protected]Primary7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
2.0[email protected]Primary4.3AV:N/AC:M/Au:N/C:N/I:N/A:P

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

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

CVSS v2.0 Breakdown

Access Vector
Network
Access Complexity
Medium
Authentication
None
Confidentiality
None
Integrity
None
Availability
Partial

AV:N/AC:M/Au:N/C:N/I:N/A:P

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Application Apache Tomcat All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Apache Software Foundation Apache Tomcat affected Apache Tomcat 8.5 8.5.0 to 8.5.63 Not specified
CNA Apache Software Foundation Apache Tomcat affected Apache Tomcat 9 9.0.0-M1 to 9.0.43 Not specified
CNA Apache Software Foundation Apache Tomcat affected Apache Tomcat 10 10.0.0-M1 to 10.0.2 Not specified

References

ReferenceSourceLinkTags
lists.apache.org/thread.html/r6b6b674e3f168dd010e67dbe6848b866e2acf26371452fda... af854a3a-2127-422b-91ae-364da2661108 lists.apache.org
Pony Mail! af854a3a-2127-422b-91ae-364da2661108 lists.apache.org Mailing List, Vendor Advisory
[SECURITY] [DLA 2764-1] tomcat8 security update af854a3a-2127-422b-91ae-364da2661108 lists.debian.org Mailing List, Third Party Advisory
CVE-2021-41079 Apache Tomcat Vulnerability in NetApp Products | NetApp Product Security af854a3a-2127-422b-91ae-364da2661108 security.netapp.com Third Party Advisory
Debian -- Security Information -- DSA-4986-1 tomcat9 af854a3a-2127-422b-91ae-364da2661108 www.debian.org Third Party Advisory
lists.apache.org/thread.html/rb4de81ac647043541a32881099aa6eb5a23f1b7fd116f713... af854a3a-2127-422b-91ae-364da2661108 lists.apache.org
Pony Mail! MITRE lists.apache.org
Pony Mail! MITRE lists.apache.org
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: The Apache Tomcat security team would like to thank Thomas Wozenilek for originally reporting this issue and David Frankson of Infinite Campus for also providing a test case that reproduced the issue. (en)

Legacy QID Mappings

  • 150385 Apache Tomcat Denial of Service Vulnerability (CVE-2021-41079)
  • 178801 Debian Security Update for tomcat8 (DLA 2764-1)
  • 182401 Debian Security Update for tomcat9 (CVE-2021-41079)
  • 198724 Ubuntu Security Notification for Tomcat Vulnerabilities (USN-5360-1)
  • 239732 Red Hat Update for red hat jboss web server 5.5.1 (RHSA-2021:3741)
  • 352859 Amazon Linux Security Advisory for tomcat8: ALAS-2021-1547
  • 671154 EulerOS Security Update for tomcat (EulerOS-SA-2021-2816)
  • 730505 Apache Tomcat Denial of Service (DoS) Vulnerability (CVE-2021-41079)
  • 751320 SUSE Enterprise Linux Security Update for tomcat (SUSE-SU-2021:3602-1)
  • 751355 OpenSUSE Security Update for tomcat (openSUSE-SU-2021:3672-1)
  • 751364 SUSE Enterprise Linux Security Update for tomcat (SUSE-SU-2021:3669-1)
  • 751365 SUSE Enterprise Linux Security Update for tomcat (SUSE-SU-2021:3670-1)
  • 751370 OpenSUSE Security Update for tomcat (openSUSE-SU-2021:1490-1)
  • 980413 Java (maven) Security Update for org.apache.tomcat:tomcat (GHSA-59g9-7gfx-c72p)

© CVE.report 2026

Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. It is the responsibility of user to evaluate the accuracy, completeness or usefulness of any information, opinion, advice or other content. EACH USER WILL BE SOLELY RESPONSIBLE FOR ANY consequences of his or her direct or indirect use of this web site. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY DISCLAIMED. This site will NOT BE LIABLE FOR ANY DIRECT, INDIRECT or any other kind of loss.

CVE, CWE, and OVAL are registred trademarks of The MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. This site includes MITRE data granted under the following license.

Free CVE JSON API cve.report/api

CVE.report and Source URL Uptime Status status.cve.report