High severity · published Oct 14, 2021
CVE-2021-42340
The fix for bug 63362 present in Apache Tomcat 10.1.0-M1 to 10.1.0-M5, 10.0.0-M1 to 10.0.11, 9.0.40 to 9.0.53 and 8.5.60 to 8.5.71 introduced a memory leak
7.5
CVSS
11.8%
EPSS
No
On KEV
Description
The fix for bug 63362 present in Apache Tomcat 10.1.0-M1 to 10.1.0-M5, 10.0.0-M1 to 10.0.11, 9.0.40 to 9.0.53 and 8.5.60 to 8.5.71 introduced a memory leak. The object introduced to collect metrics for HTTP upgrade connections was not released for WebSocket connections once the connection was closed. This created a memory leak that, over time, could lead to a denial of service via an OutOfMemoryError.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)11.8% · higher than 96% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
TO
Tomcat · Apache
8.5.60 before 8.5.72; 9.0.40 before 9.0.54; 10.0.1 before 10.0.12; 10.0.0; 10.1.0; 10.1.0; +3 more · source: NVD
AE
Agile Engineering Data Management · Oracle
6.2.1.0 · source: NVD
BD
Big Data Spatial And Graph · Oracle
before 23.1 · source: NVD
CD
Communications Diameter Signaling Router · Oracle
8.0.0.0 through 8.5.0.2 · source: NVD
DL
Debian Linux · Debian
11.0 · source: NVD
HC
Hci · Netapp
All versions, or not specified · source: NVD
HC
Hospitality Cruise Shipboard Property Management System · Oracle
20.1.0 · source: NVD
MF
Managed File Transfer · Oracle
12.2.1.3.0; 12.2.1.4.0 · source: NVD
MS
Management Services For Element Software · Netapp
All versions, or not specified · source: NVD
MC
Middleware Common Libraries And Tools · Oracle
12.2.1.4.0 · source: NVD
PI
Payment Interface · Oracle
19.1; 20.3 · source: NVD
RC
Retail Customer Insights · Oracle
15.0.2; 16.0.2 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-42340
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-42340
Third Party Advisory
https://kc.mcafee.com/corporate/index?page=content&id=SB10379
lists.apache.org
https://lists.apache.org/thread.html/r8097a2d1550aa78e585fc77e602b9046e6d4099d8d132497c5387784%40%3Ccommits.myfaces.apache.org%3E
Mailing List
https://lists.apache.org/thread.html/r83a35be60f06aca2065f188ee542b9099695d57ced2e70e0885f905c%40%3Cannounce.tomcat.apache.org%3E
Third Party Advisory
https://security.gentoo.org/glsa/202208-34
Third Party Advisory
https://security.netapp.com/advisory/ntap-20211104-0001/
Third Party Advisory
https://www.debian.org/security/2021/dsa-5009
More from Tomcat
9.8
CVE-2025-24813
Apache Tomcat: Potential RCE and/or information disclosure and/or information corruption with partial PUT
9.8
CVE-2020-1938
Apache Tomcat Improper Privilege Management Vulnerability
9.8
CVE-2016-8735
Remote code execution is possible with Apache Tomcat before 6.0.48, 7.x before 7.0.73, 8.x before 8.0.39, 8.5.x before 8.5.7, and 9.x before 9.0.0.M12 if…
8.1
CVE-2017-12617
When running Apache Tomcat versions 9.0.0.M1 to 9.0.0, 8.5.0 to 8.5.22, 8.0.0.RC1 to 8.0.46 and 7.0.0 to 7.0.81 with HTTP PUTs enabled (e.g
8.1
CVE-2017-12615
When running Apache Tomcat 7.0.0 to 7.0.79 on Windows with HTTP PUTs enabled (e.g