Vulnerability in Apache Tomcat

CVE-2021-33037

Apache Tomcat 10.0.0-M1 to 10.0.6, 9.0.0.M1 to 9.0.46 and 8.5.0 to 8.5.66 did not correctly parse the HTTP transfer-encoding request header in some circumstances leading to the possibility to request smuggling when used with a reverse prox…

Vulnerability class: HTTP Request Smuggling

EPSS: 0.754 (99.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-33037?
CVE-2021-33037 is a medium-severity vulnerability in Apache Tomcat, classified under Inconsistent Interpretation of HTTP Requests (HTTP Request/Response Smuggling). CVSS score: 5.3/10. Published 2021-07-12.
How severe is CVE-2021-33037?
Medium severity. CVSS v3 base score is 5.3 out of 10.
Is CVE-2021-33037 known to be exploited?
6 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.