Vulnerability in Apache Tomcat
CVE-2020-13943
If an HTTP/2 client connecting to Apache Tomcat 10.0.0-M1 to 10.0.0-M7, 9.0.0.M1 to 9.0.37 or 8.5.0 to 8.5.57 exceeded the agreed maximum number of concurrent streams for a connection (in violation of the HTTP/2 protocol), it was possible that a subsequent request made on that connection could contain HTTP headers - including HTTP/2 pseudo headers - from a previous request rather than the intended headers. This could lead to users seeing responses for unexpected resources.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.
EPSS exploit prediction
EPSS: 0.550 (99.0th percentile), scored .
High probability of exploitation in the next 30 days — patch promptly. 99th percentile — 99.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.573 · newest: 0.550 · change: -0.023
Affected products
- Apache Tomcat — versions 8.5.0, 8.5.1, 8.5.2
- Oracle Instantis Enterprisetrack — versions 17.1, 17.2, 17.3
- Oracle Sd-Wan Edge — versions 9.0
- Debian Linux — versions 9.0, 10.0
- Apache Tomcat — versions Apache Tomcat 10.0.0-M1 to 10.0.0-M7, 9.0.0.M1 to 9.0.37, 8.5.0 to 8.5.57
Public proof-of-concept exploits
References
- lists.apache.org/thread.html/r4a390027eb27e4550142fac6c8317cc684b157ae314d31514… (Vendor Advisory)
- lists.debian.org/debian-lts-announce/2020/10/msg00019.html (mailing-list, Third Party Advisory)
- lists.opensuse.org/opensuse-security-announce/2020-11/msg00002.html (vendor-advisory, Mailing List, Third Party Advisory)
- lists.opensuse.org/opensuse-security-announce/2020-11/msg00021.html (vendor-advisory, Broken Link)
- www.debian.org/security/2021/dsa-4835 (vendor-advisory, Third Party Advisory)
- www.oracle.com/security-alerts/cpuApr2021.html (Patch, Third Party Advisory)
- security.netapp.com/advisory/ntap-20201016-0007/ (Third Party Advisory)
Frequently asked questions
- What is CVE-2020-13943?
- CVE-2020-13943 is a medium-severity vulnerability in Apache Tomcat. CVSS score: 4.3/10. Published 2020-10-12.
- How severe is CVE-2020-13943?
- Medium severity. CVSS v3 base score is 4.3 out of 10.
- Is CVE-2020-13943 known to be exploited?
- 5 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.