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 proxy.
Does this matter?
EPSS puts the probability of exploitation in the next 30 days at 74.7%, higher than 100% of all known CVEs. Patch or mitigate before the next change window.
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.
- CVSS 3.1
- 5.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
- EPSS
- 74.67% probability · 100th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-444
- Affected
- apache/tomcat · apache/tomee · debian/debian linux · oracle/agile product lifecycle management · oracle/communications cloud native core policy · oracle/communications cloud native core service communication proxy · oracle/communications diameter signaling router · oracle/communications instant messaging server · oracle/communications policy management · oracle/communications pricing design center · oracle/communications session report manager · oracle/communications session route manager · oracle/graph server and client · oracle/healthcare translational research · oracle/hospitality cruise shipboard property management system · oracle/instantis enterprisetrack · oracle/managed file transfer · oracle/mysql enterprise monitor · oracle/sd-wan edge · oracle/secure global desktop · +2 more
- Source
- security@apache.org
EPSS 74.7% since 3 November 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://kc.mcafee.com/corporate/index?page=content&id=SB10366Third Party Advisory
- https://lists.apache.org/thread.html/r290aee55b72811fd19e75ac80f6143716c079170c5671b96932ed44b%40%3Ccommits.tomee.apache.org%3E
- https://lists.apache.org/thread.html/r40f921575aee8d7d34e53182f862c45cbb8f3d898c9d4e865c2ec262%40%3Ccommits.tomee.apache.org%3E
- https://lists.apache.org/thread.html/r612a79269b0d5e5780c62dfd34286a8037232fec0bc6f1a7e60c9381%40%3Cannounce.tomcat.apache.org%3EMailing List, Vendor Advisory
- https://lists.apache.org/thread.html/rc6ef52453bb996a98cb45442871a1db56b7c349939e45d829bf9ae37%40%3Ccommits.tomee.apache.org%3E
- https://lists.apache.org/thread.html/rd0dfea39829bc0606c936a16f6fca338127c86c0a1083970b45ac8d2%40%3Ccommits.tomee.apache.org%3E
- https://lists.apache.org/thread.html/re01e7e93154e8bdf78a11a23f9686427bd3d51fc6e12c508645567b7%40%3Ccommits.tomee.apache.org%3E
- https://lists.apache.org/thread.html/rf1b54fd3f52f998ca4829159a88cc4c23d6cef5c6447d00948e75c97%40%3Ccommits.tomee.apache.org%3E
- https://lists.debian.org/debian-lts-announce/2021/08/msg00009.htmlMailing List, Third Party Advisory
- https://security.gentoo.org/glsa/202208-34Third Party Advisory
- https://security.netapp.com/advisory/ntap-20210827-0007/Third Party Advisory
- https://www.debian.org/security/2021/dsa-4952Third Party Advisory
- https://www.oracle.com//security-alerts/cpujul2021.htmlPatch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpuapr2022.htmlPatch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpujan2022.htmlPatch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpuoct2021.htmlPatch, Third Party Advisory
- https://kc.mcafee.com/corporate/index?page=content&id=SB10366Third Party Advisory
- https://lists.apache.org/thread.html/r290aee55b72811fd19e75ac80f6143716c079170c5671b96932ed44b%40%3Ccommits.tomee.apache.org%3E
- https://lists.apache.org/thread.html/r40f921575aee8d7d34e53182f862c45cbb8f3d898c9d4e865c2ec262%40%3Ccommits.tomee.apache.org%3E
- https://lists.apache.org/thread.html/r612a79269b0d5e5780c62dfd34286a8037232fec0bc6f1a7e60c9381%40%3Cannounce.tomcat.apache.org%3EMailing List, Vendor Advisory
- https://lists.apache.org/thread.html/rc6ef52453bb996a98cb45442871a1db56b7c349939e45d829bf9ae37%40%3Ccommits.tomee.apache.org%3E
- https://lists.apache.org/thread.html/rd0dfea39829bc0606c936a16f6fca338127c86c0a1083970b45ac8d2%40%3Ccommits.tomee.apache.org%3E
- https://lists.apache.org/thread.html/re01e7e93154e8bdf78a11a23f9686427bd3d51fc6e12c508645567b7%40%3Ccommits.tomee.apache.org%3E
- https://lists.apache.org/thread.html/rf1b54fd3f52f998ca4829159a88cc4c23d6cef5c6447d00948e75c97%40%3Ccommits.tomee.apache.org%3E
- https://lists.debian.org/debian-lts-announce/2021/08/msg00009.htmlMailing List, Third Party Advisory
- https://security.gentoo.org/glsa/202208-34Third Party Advisory
- https://security.netapp.com/advisory/ntap-20210827-0007/Third Party Advisory
- https://www.debian.org/security/2021/dsa-4952Third Party Advisory
- https://www.oracle.com//security-alerts/cpujul2021.htmlPatch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpuapr2022.htmlPatch, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.