🛡️ CVE-2021-33037 — tomcat

🟡 CVSS 5.0 — Medium ✅ No Known Exploit CWE-444 OSV
5.0
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

Incorrect Transfer-Encoding handling with HTTP/1.0

Apache Tomcat 10.0.0 to 10.0.6, 9.0.0 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 proxy. Specifically: - Tomcat incorrectly ignored the transfer encoding header if the client declared it would only accept an HTTP/1.0 response; - Tomcat honoured the identify encoding; and - Tomcat did not ensure that, if present, the chunked encoding was the final encoding.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality none, integrity low, availability none.

Weakness class

CVE-2021-33037 is classified as CWE-444: HTTP Request Smuggling. A proxy and a server disagree on where one request ends, letting an attacker slip a second request past the front end.

Affected software

CVE-2021-33037 is recorded against 2 packages.

  • org.apache.tomcat:tomcat (from 8.5.0 up to 8.5.68)
  • tomcat

Timeline and source

Published on 13 August 2021 and last revised on 11 March 2024. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

nvd.nist.gov (Advisory)
github.com (Web)
github.com (Web)
github.com (Web)
github.com (Web)
github.com (Web)
github.com (Web)
github.com (Web)
github.com (Web)
github.com (Web)
security.gentoo.org (Web)
security.netapp.com (Web)
tomcat.apache.org (Web)
tomcat.apache.org (Web)
tomcat.apache.org (Web)

CVE-2021-33037 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Details

Severity Medium
CVSS Score 5.0
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
CWE CWE-444
Public Exploit ✅ No
Source OSV
Published 2021-08-13
Updated 2026-08-12
Modified 2024-03-11
Fix URL N/A

Affected Packages

Software From version Fixed in
org.apache.tomcat:tomcat 8.5.0 8.5.68
tomcat — —

References

Vulnerability Monitoring

Track new vulnerabilities in tomcat

CVE-2021-33037 is rated CVSS 5.0 Medium. BotEraser monitors your WordPress installation and notifies you when software you use appears in our vulnerability database.

Set Up Free Alerts →

No credit card required  ·  Results in minutes

ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.