SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

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…

MEDIUM 4.3EPSS 57.3%

Does this matter?

EPSS puts the probability of exploitation in the next 30 days at 57.3%, higher than 99% of all known CVEs. Patch or mitigate before the next change window.

Description

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.

CVSS 3.1
4.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
EPSS
57.29% probability · 99th percentile
CISA KEV
Not listed
Affected
apache/tomcat · debian/debian linux · oracle/instantis enterprisetrack · oracle/sd-wan edge
Source
security@apache.org

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.