CVE-2020-13934
High
High exploit probability or critical severity with a known exploit.
CVSS base
7.5
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS — probability of exploitation (30 days)
64.1%
99.2th percentile
CISA KEV
Not listed
Weakness / dates
CWE-401
Published 2020-07-14 · modified 2026-08-25
CVSS breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
| Attack Vector | N | Network |
| Attack Complexity | L | Low |
| Privileges Required | N | None |
| User Interaction | N | None |
| Scope | U | Unchanged |
| Confidentiality | N | None |
| Integrity | N | None |
| Availability | H | High |
Timeline
- 2020-07-14 — Published (NVD)
- 2026-08-25 — Last modified (NVD)
Description
An h2c direct connection to Apache Tomcat 10.0.0-M1 to 10.0.0-M6, 9.0.0.M5 to 9.0.36 and 8.5.1 to 8.5.56 did not release the HTTP/1.1 processor after the upgrade to HTTP/2. If a sufficient number of such requests were made, an OutOfMemoryException could occur leading to a denial of service.
Affected
References
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00084.html
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00088.html
- https://lists.apache.org/thread.html/r61f411cf82488d6ec213063fc15feeeb88e31b0ca9c29652ee4f962e%40%3Cannounce.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/ra072b1f786e7d139e86f1d1145572e0ff71cef38a96d9c6f5362aac8%40%3Cdev.tomcat.apache.org%3E
- https://lists.debian.org/debian-lts-announce/2020/07/msg00017.html
- https://security.netapp.com/advisory/ntap-20200724-0003/
- https://usn.ubuntu.com/4596-1/
- https://www.debian.org/security/2020/dsa-4727
- https://www.oracle.com//security-alerts/cpujul2021.html
- https://www.oracle.com/security-alerts/cpuApr2021.html
- https://www.oracle.com/security-alerts/cpujan2021.html
- https://www.oracle.com/security-alerts/cpujan2022.html
- https://www.oracle.com/security-alerts/cpuoct2020.html
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00084.html
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00088.html
- https://lists.apache.org/thread.html/r61f411cf82488d6ec213063fc15feeeb88e31b0ca9c29652ee4f962e%40%3Cannounce.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/ra072b1f786e7d139e86f1d1145572e0ff71cef38a96d9c6f5362aac8%40%3Cdev.tomcat.apache.org%3E
- https://lists.debian.org/debian-lts-announce/2020/07/msg00017.html
- https://security.netapp.com/advisory/ntap-20200724-0003/
- https://usn.ubuntu.com/4596-1/
- https://www.debian.org/security/2020/dsa-4727
- https://www.oracle.com//security-alerts/cpujul2021.html
- https://www.oracle.com/security-alerts/cpuApr2021.html
- https://www.oracle.com/security-alerts/cpujan2021.html
- https://www.oracle.com/security-alerts/cpujan2022.html
- https://www.oracle.com/security-alerts/cpuoct2020.html