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.
EPSS: 0.069 (93.7th percentile) — read the EPSS interpretation.
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.
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
- security@apache.org (Mailing List, x_refsource_MISC, Vendor Advisory)
- security@apache.org (mailing-list, x_refsource_MLIST)
- security@apache.org (mailing-list, x_refsource_MLIST)
- security@apache.org (x_refsource_CONFIRM, Third Party Advisory)
- security@apache.org (x_refsource_CONFIRM, Third Party Advisory)
- security@apache.org (Patch, Third Party Advisory, x_refsource_MISC)
- security@apache.org (vendor-advisory, Third Party Advisory, x_refsource_GENTOO)
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.