CVE-2021-43980 - CVE House
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Status published Unknown CVE-2021-43980

Apache Tomcat: Information disclosure

Vulnerability Description

The simplified implementation of blocking reads and writes introduced in Tomcat 10 and back-ported to Tomcat 9.0.47 onwards exposed a long standing (but extremely hard to trigger) concurrency bug in Apache Tomcat 10.1.0 to 10.1.0-M12, 10.0.0-M1 to 10.0.18, 9.0.0-M1 to 9.0.60 and 8.5.0 to 8.5.77 that could cause client connections to share an Http11Processor instance resulting in responses, or part responses, to be received by the wrong client.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

The following person or organization is credited with identifying this vulnerability, as recorded in the NVD database:

  • Thanks to Adam Thomas, Richard Hernandez and Ryan Schmitt for discovering the issue and working with the Tomcat security team to identify the root cause and appropriate fix.

Affected Vendor

Apache Software Foundation

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Affected Software

Apache Tomcat
Vulnerable Versions:
10.1.0-M1 to 10.1.0-M12, 10.0.0-M1 to 10.0.18, 9.0.0-M1 to 9.0.60, 8.5.0 to 8.5.77

Timeline

Official Publish: September 28th, 2022
Last Modified: May 21st, 2025
Added to House: July 21st, 2026

CVSS Vectors

No vector data available

Weaknesses (CWE)