CVE-2021-25122
HighCVSS 7.5Exploitation Probability (EPSS)
Very high risk97th percentile - higher than 97% of all known CVEs
Summary
When responding to new h2c connection requests, Apache Tomcat versions 10.0.0-M1 to 10.0.0, 9.0.0.M1 to 9.0.41 and 8.5.0 to 8.5.61 could duplicate request headers and a limited amount of request body from one request to another meaning user A and user B could both see the results of user A's request.
Risk Assessment
This could lead to data disclosure between users, compromising confidentiality and session isolation.
Recommendation
Update Apache Tomcat to a version containing the fix (e.g., 10.0.1, 9.0.42, 8.5.62 or later).
Original NVD description (English source)
When responding to new h2c connection requests, Apache Tomcat versions 10.0.0-M1 to 10.0.0, 9.0.0.M1 to 9.0.41 and 8.5.0 to 8.5.61 could duplicate request headers and a limited amount of request body from one request to another meaning user A and user B could both see the results of user A's request.