Vulnerability in Apache Tomcat
CVE-2021-30639
A vulnerability in Apache Tomcat allows an attacker to remotely trigger a denial of service. An error introduced as part of a change to improve error handling during non-blocking I/O meant that the error flag associated with the Request object was not reset between requests. This meant that once a non-blocking I/O error occurred, all future requests handled by that request object would fail. Users were able to trigger non-blocking I/O errors, e.g. by dropping a connection, thereby creating the possibility of triggering a DoS. Applications that do not use non-blocking I/O are not exposed to this vulnerability. This issue affects Apache Tomcat 10.0.3 to 10.0.4; 9.0.44; 8.5.64.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.069 (94.1th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 94th percentile — 94.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.069 · newest: 0.069 · change: 0.000
Affected products
- Apache Tomcat — versions 8.5.64, 9.0.44, 10.0.3
- Apache Software Foundation Tomcat — versions Apache Tomcat 10 10.0.3 to 10.0.4, Apache Tomcat 9 9.0.44, Apache Tomcat 8.5 8.5.64
- Mcafee Epolicy Orchestrator — versions 5.10.0
- Oracle Big Data Spatial And Graph
Weakness classification (CWE)
Public proof-of-concept exploits
References
- lists.apache.org/thread.html/rd84fae1f474597bdf358f5bdc0a5c453c507bd527b83e8be6… (Mailing List, Vendor Advisory)
- lists.apache.org/thread.html/r79a7c019712b39aedf7cf4da9276d80610f04441b2a4f6506… (mailing-list)
- lists.apache.org/thread.html/r79a7c019712b39aedf7cf4da9276d80610f04441b2a4f6506… (mailing-list)
- security.netapp.com/advisory/ntap-20210827-0007/ (Third Party Advisory)
- kc.mcafee.com/corporate/index (Third Party Advisory)
- www.oracle.com/security-alerts/cpujan2022.html (Patch, Third Party Advisory)
- security.gentoo.org/glsa/202208-34 (vendor-advisory, Third Party Advisory)
Frequently asked questions
- What is CVE-2021-30639?
- CVE-2021-30639 is a high-severity vulnerability in Apache Tomcat, classified under Improper Handling of Exceptional Conditions. CVSS score: 7.5/10. Published 2021-07-12.
- How severe is CVE-2021-30639?
- High severity. CVSS v3 base score is 7.5 out of 10.
- Is CVE-2021-30639 known to be exploited?
- 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.