CVE-2020-13943
MEDIUM severity · CVSS 4.3
4.3CVSS MEDIUM
Summary
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.
Impact & exploitability
Attack vectorNetwork
Attack complexityLow
Privileges requiredLow
User interactionNone
Confidentiality impactLow
Integrity impactNone
Availability impactNone
Exploit probability (EPSS)55%
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Affected products we track (2)
Recommendation
Apply the vendor fix in your normal patch cycle. Open any affected product above for its exact safe version.
Official patch: https://www.oracle.com/security-alerts/cpuApr2021.html ↗
Additional information
- NVD record
- https://www.oracle.com/security-alerts/cpuApr2021.htmlPatch
- https://lists.apache.org/thread.html/r4a390027eb27e4550142fac6c8317cc684b157ae314d31514747f307%40%3Cannounce.tomcat.apache.org%3EAdvisory
- http://lists.opensuse.org/opensuse-security-announce/2020-11/msg00002.htmlAdvisory
- http://lists.opensuse.org/opensuse-security-announce/2020-11/msg00021.html
- https://lists.debian.org/debian-lts-announce/2020/10/msg00019.htmlAdvisory
- https://security.netapp.com/advisory/ntap-20201016-0007/Advisory
- https://www.debian.org/security/2021/dsa-4835Advisory