Apache Tomcat h2c request mix-up

MITRE NVD CVE.ORG JSON API Print: PDF PDF

Summary

CVECVE-2021-25122
StatePUBLISHED
Assignerapache
Source PriorityCVE Program / NVD first with legacy fallback
Published2021-03-01 12:15:13 UTC
Updated2026-08-25 16:28:27 UTC
DescriptionWhen responding to new h2c connection requests, Apache Tomcat versions 10.0.0-M1 to 10.0.0, 9.0.0.M1 to 9.0.41 and 8.5.0 to 8.5.61 could duplicate request headers and a limited amount of request body from one request to another meaning user A and user B could both see the results of user A's request.

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:H/I:N/A:N

EPSS: 0.181140000 probability, percentile 0.969710000 (date 2026-08-25)

Problem Types: CWE-200 | CWE-200 CWE-200 Information Exposure

VersionSourceTypeScoreSeverityVector
3.1[email protected]Primary7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
2.0[email protected]Primary5AV:N/AC:L/Au:N/C:P/I:N/A:N

CVSS v3.1 Breakdown

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

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

CVSS v2.0 Breakdown

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

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

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Application Apache Tomcat 10.0.0 - All All
Application Apache Tomcat 10.0.0 milestone1 All All
Application Apache Tomcat 10.0.0 milestone10 All All
Application Apache Tomcat 10.0.0 milestone2 All All
Application Apache Tomcat 10.0.0 milestone3 All All
Application Apache Tomcat 10.0.0 milestone4 All All
Application Apache Tomcat 10.0.0 milestone5 All All
Application Apache Tomcat 10.0.0 milestone6 All All
Application Apache Tomcat 10.0.0 milestone7 All All
Application Apache Tomcat 10.0.0 milestone8 All All
Application Apache Tomcat 10.0.0 milestone9 All All
Application Apache Tomcat 9.0.0 milestone1 All All
Application Apache Tomcat 9.0.0 milestone10 All All
Application Apache Tomcat 9.0.0 milestone11 All All
Application Apache Tomcat 9.0.0 milestone12 All All
Application Apache Tomcat 9.0.0 milestone13 All All
Application Apache Tomcat 9.0.0 milestone14 All All
Application Apache Tomcat 9.0.0 milestone15 All All
Application Apache Tomcat 9.0.0 milestone16 All All
Application Apache Tomcat 9.0.0 milestone17 All All
Application Apache Tomcat 9.0.0 milestone18 All All
Application Apache Tomcat 9.0.0 milestone19 All All
Application Apache Tomcat 9.0.0 milestone2 All All
Application Apache Tomcat 9.0.0 milestone20 All All
Application Apache Tomcat 9.0.0 milestone21 All All
Application Apache Tomcat 9.0.0 milestone22 All All
Application Apache Tomcat 9.0.0 milestone23 All All
Application Apache Tomcat 9.0.0 milestone24 All All
Application Apache Tomcat 9.0.0 milestone25 All All
Application Apache Tomcat 9.0.0 milestone26 All All
Application Apache Tomcat 9.0.0 milestone27 All All
Application Apache Tomcat 9.0.0 milestone3 All All
Application Apache Tomcat 9.0.0 milestone4 All All
Application Apache Tomcat 9.0.0 milestone5 All All
Application Apache Tomcat All All All All
Application Apache Tomcat All All All All
Operating System Debian Debian Linux 10.0 All All All
Operating System Debian Debian Linux 9.0 All All All
Application Oracle Agile Product Lifecycle Management 9.3.3 All All All
Application Oracle Agile Product Lifecycle Management 9.3.6 All All All
Application Oracle Communications Cloud Native Core Policy 1.14.0 All All All
Application Oracle Communications Cloud Native Core Security Edge Protection Proxy 1.6.0 All All All
Application Oracle Communications Instant Messaging Server 10.0.1.5.0 All All All
Application Oracle Database 12.2.0.1 All All All
Application Oracle Database 19c All All All
Application Oracle Database 21c All All All
Application Oracle Graph Server And Client All All All All
Application Oracle Graph Server And Client 21.3.0 All All All
Application Oracle Instantis Enterprisetrack 17.1 All All All
Application Oracle Instantis Enterprisetrack 17.2 All All All
Application Oracle Instantis Enterprisetrack 17.3 All All All
Application Oracle Managed File Transfer 12.2.1.3.0 All All All
Application Oracle Managed File Transfer 12.2.1.4.0 All All All
Application Oracle Mysql Enterprise Monitor All All All All
Application Oracle Siebel Ui Framework All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Apache Software Foundation Apache Tomcat affected Apache Tomcat 10 10.0.2 custom Not specified
CNA Apache Software Foundation Apache Tomcat affected Apache Tomcat 9 9.0.42 custom Not specified
CNA Apache Software Foundation Apache Tomcat affected Apache Tomcat 8.5 8.5.62 custom Not specified

References

ReferenceSourceLinkTags
March 2021 Apache Tomcat Vulnerabilities in NetApp Products | NetApp Product Security af854a3a-2127-422b-91ae-364da2661108 security.netapp.com Third Party Advisory
Oracle Critical Patch Update Advisory - October 2021 af854a3a-2127-422b-91ae-364da2661108 www.oracle.com Patch, Third Party Advisory
Oracle Critical Patch Update Advisory - July 2021 af854a3a-2127-422b-91ae-364da2661108 www.oracle.com Patch, Third Party Advisory
lists.apache.org/thread.html/rcd90bf36b1877e1310b87ecd14ed7bbb15da52b297efd9f0... af854a3a-2127-422b-91ae-364da2661108 lists.apache.org
Oracle Critical Patch Update Advisory - January 2022 af854a3a-2127-422b-91ae-364da2661108 www.oracle.com Patch, Third Party Advisory
[SECURITY] [DLA 2596-1] tomcat8 security update af854a3a-2127-422b-91ae-364da2661108 lists.debian.org Mailing List, Third Party Advisory
lists.apache.org/thread.html/r7b95bc248603360501f18c8eb03bb6001ec0ee3296205b34... af854a3a-2127-422b-91ae-364da2661108 lists.apache.org
Pony Mail! af854a3a-2127-422b-91ae-364da2661108 lists.apache.org Mailing List, Vendor Advisory
lists.apache.org/thread.html/rd0463f9a5cbc02a485404c4b990f0da452e5ac5c237808ed... af854a3a-2127-422b-91ae-364da2661108 lists.apache.org
Apache Tomcat: Multiple Vulnerabilities (GLSA 202208-34) — Gentoo security af854a3a-2127-422b-91ae-364da2661108 security.gentoo.org Third Party Advisory
oss-security - CVE-2021-25122: Apache Tomcat h2c request mix-up af854a3a-2127-422b-91ae-364da2661108 www.openwall.com Mailing List, Third Party Advisory
Debian -- Security Information -- DSA-4891-1 tomcat9 af854a3a-2127-422b-91ae-364da2661108 www.debian.org Third Party Advisory
lists.apache.org/thread.html/rf6d5d57b114678d8898005faef31e9fd6d7c981fcc4ccfc3... af854a3a-2127-422b-91ae-364da2661108 lists.apache.org
lists.apache.org/thread.html/r7b95bc248603360501f18c8eb03bb6001ec0ee3296205b34... af854a3a-2127-422b-91ae-364da2661108 lists.apache.org
lists.apache.org/thread.html/r7b95bc248603360501f18c8eb03bb6001ec0ee3296205b34... af854a3a-2127-422b-91ae-364da2661108 lists.apache.org
Pony Mail! MITRE lists.apache.org
Pony Mail! MITRE lists.apache.org
Pony Mail! MITRE lists.apache.org
Pony Mail! MITRE lists.apache.org
Pony Mail! MITRE 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

Legacy QID Mappings

  • 150452 Apache Tomcat h2c request mix-up vulnerability (CVE-2021-25122)
  • 174905 SUSE Enterprise Linux Security Update for tomcat (SUSE-SU-2021:0988-1)
  • 174906 SUSE Enterprise Linux Security Update for tomcat (SUSE-SU-2021:0989-1)
  • 174912 SUSE Enterprise Linux Security Update for tomcat (SUSE-SU-2021:1009-1)
  • 174941 SUSE Enterprise Linux Security Update for tomcat (SUSE-SU-2021:1008-1)
  • 178492 Debian Security Update for tomcat8 (DLA 2596-1)
  • 178533 Debian Security Update for tomcat9 (DSA 4891-1)
  • 179657 Debian Security Update for tomcat9 (CVE-2021-25122)
  • 198724 Ubuntu Security Notification for Tomcat Vulnerabilities (USN-5360-1)
  • 20232 Oracle Database 21c Critical Patch Update - October 2021
  • 20233 Oracle Database 19c Critical Patch Update - October 2021
  • 20234 Oracle Database 12.2.0.1 Critical Patch Update - October 2021
  • 20235 Oracle Database 12.2.0.1 Critical Patch Update - October 2021 (Unauthenticated)
  • 20270 Oracle Database 21c Critical Patch Update - October 2022
  • 20271 Oracle Database 19c Critical Patch Update - October 2022
  • 20272 Oracle Database 19c Critical OJVM Patch Update - October 2022
  • 20276 Oracle Database 19c Critical OJVM Patch Update - October 2021
  • 20290 Oracle Database 12.2.0.1 Critical OJVM Patch Update - October 2021
  • 239760 Red Hat Update for red hat jboss web server 5.5.0 (RHSA-2021:2561)
  • 352256 Amazon Linux Security Advisory for tomcat8: ALAS-2021-1491
  • 356300 Amazon Linux Security Advisory for tomcat : ALASTOMCAT8.5-2023-009
  • 670333 EulerOS Security Update for tomcat (EulerOS-SA-2021-1891)
  • 710609 Gentoo Linux Apache Tomcat Multiple Vulnerabilities (GLSA 202208-34)
  • 730041 Apache Tomcat Duplicate Request Headers Vulnerabilities
  • 730042 Apache Tomcat Duplicate Request Headers Vulnerabilities
  • 730059 Atlassian Jira Server Multiple Security Vulnerabilities(JRASERVER-72211)
  • 730470 Atlassian Confluence Tomcat Vulnerability (CONFSERVER-62837)
  • 730656 Apache Tomcat Request mix-up with h2c Vulnerability (CVE-2021-25122)
  • 730662 Apache Tomcat Request mix-up with h2c Vulnerability (CVE-2021-25122)
  • 730668 Apache Tomcat Request mix-up with h2c Vulnerability (CVE-2021-25122)
  • 750285 OpenSUSE Security Update for tomcat (openSUSE-SU-2021:0496-1)
  • 980337 Java (maven) Security Update for org.apache.tomcat.embed:tomcat-embed-core (GHSA-j39c-c8hj-x4j3)

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