CVE-2020-13943

high-risk
Published 2020-10-12

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.

Do I need to act?

~
9.6% chance of exploitation in next 30 days
EPSS score — moderate exploit probability
-
Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
4
CVSS 4.3/10 Medium
NETWORK / LOW complexity

Affected Products (20)

Affected Vendors

Debian Apache Oracle

References (14)

Mailing List http://lists.opensuse.org/opensuse-security-announce/2020-11/msg00002.html
Broken Link http://lists.opensuse.org/opensuse-security-announce/2020-11/msg00021.html
Vendor Advisory https://lists.apache.org/thread.html/r4a390027eb27e4550142fac6c8317cc684b157ae31...
Third Party Advisory https://lists.debian.org/debian-lts-announce/2020/10/msg00019.html
Third Party Advisory https://security.netapp.com/advisory/ntap-20201016-0007/
Third Party Advisory https://www.debian.org/security/2021/dsa-4835
Patch https://www.oracle.com/security-alerts/cpuApr2021.html
Mailing List http://lists.opensuse.org/opensuse-security-announce/2020-11/msg00002.html
Broken Link http://lists.opensuse.org/opensuse-security-announce/2020-11/msg00021.html
Vendor Advisory https://lists.apache.org/thread.html/r4a390027eb27e4550142fac6c8317cc684b157ae31...
Third Party Advisory https://lists.debian.org/debian-lts-announce/2020/10/msg00019.html
Third Party Advisory https://security.netapp.com/advisory/ntap-20201016-0007/
Third Party Advisory https://www.debian.org/security/2021/dsa-4835
Patch https://www.oracle.com/security-alerts/cpuApr2021.html
61
/ 100
high-risk
Severity 18/34 · Moderate
Exploitability 11/34 · Low
Exposure 32/34 · Critical