CVE-2021-42340
HIGH7.5EPSS 4.3%DoS via memory leak with WebSocket connections
Published: 10/15/2021Modified: 4/28/2026
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.
Affected packages (4)
- Bitnami/tomcat>= 8.5.60, < 8.5.72, >= 9.0.40, < 9.0.54, >= 10.0.1, < 10.0.12
- Debian/tomcat9from 0, < 9.0.43-2~deb11u3
- Debian/tomcat9from 0, < 9.0.43-2~deb11u3
- Maven/org.apache.tomcat:tomcat>= 10.1.0-M1, < 10.1.0-M6
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
References (21)
- ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2021-42340
- ADVISORYhttps://security-tracker.debian.org/tracker/CVE-2021-42340
- PATCHhttps://github.com/apache/tomcat
- WEBhttps://github.com/apache/tomcat/commit/31d62426645824bdfe076a0c0eafa904d90b4fb9
- WEBhttps://github.com/apache/tomcat/commit/80f1438ec45e77a07b96419808971838d259eb47
- WEBhttps://github.com/apache/tomcat/commit/d27535bdee95d252418201eb21e9d29476aa6b6a
- WEBhttps://github.com/apache/tomcat/commit/d5a6660cba7f51589468937bf3bbad4db7810371
- WEBhttps://kc.mcafee.com/corporate/index?page=content&id=SB10379
- WEBhttps://lists.apache.org/thread.html/r8097a2d1550aa78e585fc77e602b9046e6d4099d8d132497c5387784@%3Ccommits.myfaces.apache.org%3E
- WEBhttps://lists.apache.org/thread.html/r8097a2d1550aa78e585fc77e602b9046e6d4099d8d132497c5387784%40%3Ccommits.myfaces.apache.org%3E
- WEBhttps://lists.apache.org/thread.html/r83a35be60f06aca2065f188ee542b9099695d57ced2e70e0885f905c%40%3Cannounce.tomcat.apache.org%3E
- WEBhttps://security.gentoo.org/glsa/202208-34
- WEBhttps://security.netapp.com/advisory/ntap-20211104-0001
- WEBhttps://security.netapp.com/advisory/ntap-20211104-0001/
- WEBhttps://tomcat.apache.org/security-10.html
- WEBhttps://tomcat.apache.org/security-8.html
- WEBhttps://tomcat.apache.org/security-9.html
- WEBhttps://www.debian.org/security/2021/dsa-5009
- WEBhttps://www.oracle.com/security-alerts/cpuapr2022.html
- WEBhttps://www.oracle.com/security-alerts/cpujan2022.html
- WEBhttps://www.oracle.com/security-alerts/cpujul2022.html