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.
Source: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-1935
Reference (s):
- https://security.netapp.com/advisory/ntap-20200327-0005/
- URL: https://security.netapp.com/advisory/ntap-20200327-0005/
- DEBIAN:DSA-4673
- URL: https://www.debian.org/security/2020/dsa-4673
- DEBIAN:DSA-4680