CVE-2020-1935

medium
Published 2020-02-28 · Modified 2026-05-18
CVSS v3
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
CVSS v2
VIR risk
5.5

Description

In Apache Tomcat 9.0.0.M1 to 9.0.30, 8.5.0 to 8.5.50 and 7.0.0 to 7.0.99 the HTTP header parsing code used an approach to end-of-line parsing that allowed some invalid HTTP headers to be parsed as valid. This led to a possibility of HTTP Request Smuggling if Tomcat was located behind a reverse proxy that incorrectly handled the invalid Transfer-Encoding header in a particular manner. Such a reverse proxy is considered unlikely.

Predictions

Exploit likelihood
30%
Patch ETA

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

vendor Authored 2026-05-27

Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2020-1935

vendor Authored 2026-05-27

Vendor advisory: rocky — https://errata.rockylinux.org/RLSA-2020:4847

OS impact

OSVersionStatusFixed in
rockylinux rocky8fixed
debian debianbookwormfixed9.0.31-1
debian debianbullseyefixed9.0.31-1
debian debianforkyfixed9.0.31-1
debian debiansidfixed9.0.31-1
debian debiantrixiefixed9.0.31-1

Package impact

EcosystemPackageVulnerableFixed
java Mavenorg.apache.tomcat.embed:tomcat-embed-core<7.0.1007.0.100
java Mavenorg.apache.tomcat.embed:tomcat-embed-core>=8.0.0,<8.5.518.5.51
java Mavenorg.apache.tomcat.embed:tomcat-embed-core>=9.0.0,<9.0.319.0.31
java Mavenorg.apache.tomcat:tomcat<7.0.1007.0.100
java Mavenorg.apache.tomcat:tomcat>=8.0.0,<8.5.518.5.51
java Mavenorg.apache.tomcat:tomcat>=9.0.0,<9.0.319.0.31

References

Verify integrity in audit chain (admin only). AS-IS.