CVE-2021-33037: Apache Incorrect Transfer-Encoding handling with HTTP/1.0
This Apache advisory covers CVE-2021-33037 in Apache Tomcat.
- CVE-2021-33037
Key facts
- CISA KEV
- Not listed (catalogue checked )
- Affected
- Apache Tomcat Apache Tomcat 10 10.0.0-M1 to 10.0.6; Apache Tomcat Apache Tomcat 9 9.0.0.M1 to 9.0.46; Apache Tomcat Apache Tomcat 8 8.5.0 to 8.5.66
- Source published
- Source revised
- Listed by VulniPulse
Compiled by VulniPulse from the linked sources. How records are collected and checked.
Affected products & platforms
Description
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 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.
Text from the source record.
- Apache Tomcat Apache Tomcat 10 10.0.0-M1 to 10.0.6
- Apache Tomcat Apache Tomcat 9 9.0.0.M1 to 9.0.46
- Apache Tomcat Apache Tomcat 8 8.5.0 to 8.5.66
Official advisory · medium-confidence parse· fetched ·verify at source
End-of-life dates for Apache Tomcat
More Apache Software Foundation advisories
CVE-2026-103119Oct 20, 2026Buffer under-read vulnerability in Apache Tomcat meantCVE-2026-101356Oct 20, 2026Incorrect object recycling and re-use vulnerability in Apache TomcatCVE-2026-101296Oct 20, 2026Apache Tomcat: JNDIRealm bind credential validation fails open for non-GSSAPI SASLCVE-2026-93446Oct 20, 2026Apache Tomcat: Possible TLS 1.3 connection failuresCVE-2026-88041Oct 20, 2026Apache Tomcat: HTTP/2 trailer header cross-contaminationCVE-2026-80353Oct 20, 2026Apache Tomcat: TOCTOU
Apache Software Foundation advisories, July 2021All Apache Software Foundation advisories
Get an email when Apache Tomcat publishes the next one.
See Apache Tomcat's last 90 days of advisories first. Then choose one product with live alerts free for life, or a free month of real-time alerts on everything with the severity, the fixed version and the vendor's link (card needed, then US$15/month; we email you before the first charge).
iPhone and Android apps · New on the App Store
Monitor future Apache Software Foundation CVEs from your phone.
Choose a whole vendor or a precise platform, then receive matching security advisories by phone notification, email, or both. Coverage follows 34 official vendor sources and 160+ reviewed platform categories.
