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 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.
Vulnerability class: HTTP Request Smuggling
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.747 (99.5th percentile), scored .
High probability of exploitation in the next 30 days — patch promptly. 99th percentile — 99.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.747 · newest: 0.747 · change: 0.000
Affected products
- Apache Tomcat
- Apache Tomee — versions 8.0.6
- Apache Software Foundation Tomcat — versions Apache Tomcat 10 10.0.0-M1 to 10.0.6, Apache Tomcat 9 9.0.0.M1 to 9.0.46, Apache Tomcat 8 8.5.0 to 8.5.66
- Mcafee Epolicy Orchestrator — versions 5.10.0
- Oracle Agile Plm — versions 9.3.6
- Oracle Agile Product Lifecycle Management — versions 9.3.6
- Oracle Communications Cloud Native Core Policy — versions 1.14.0
- Oracle Communications Cloud Native Core Service Communication Proxy — versions 1.14.0
- Oracle Communications Diameter Signaling Router
- Oracle Communications Instant Messaging Server — versions 10.0.1.5.0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- lists.apache.org/thread.html/r612a79269b0d5e5780c62dfd34286a8037232fec0bc6f1a7e… (Mailing List, Vendor Advisory)
- www.oracle.com//security-alerts/cpujul2021.html (Patch, Third Party Advisory)
- lists.apache.org/thread.html/r40f921575aee8d7d34e53182f862c45cbb8f3d898c9d4e865… (mailing-list)
- lists.apache.org/thread.html/re01e7e93154e8bdf78a11a23f9686427bd3d51fc6e12c5086… (mailing-list)
- lists.debian.org/debian-lts-announce/2021/08/msg00009.html (mailing-list, Mailing List, Third Party Advisory)
- www.debian.org/security/2021/dsa-4952 (vendor-advisory, Third Party Advisory)
- lists.apache.org/thread.html/rd0dfea39829bc0606c936a16f6fca338127c86c0a1083970b… (mailing-list)
- lists.apache.org/thread.html/r290aee55b72811fd19e75ac80f6143716c079170c5671b969… (mailing-list)
- lists.apache.org/thread.html/rf1b54fd3f52f998ca4829159a88cc4c23d6cef5c6447d0094… (mailing-list)
- lists.apache.org/thread.html/rc6ef52453bb996a98cb45442871a1db56b7c349939e45d829… (mailing-list)
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.