The fix for CVE-2019-0199 was incomplete and did not address HTTP/2 connection window exhaustion on write in Apache Tomcat versions 9.0.0.M1 to 9.0.19 and 8.5.0 to 8.5.40 . By not sending WINDOW_UPDATE messages for the connection window (stream 0) clients were able to cause server-side threads to block eventually leading to thread exhaustion and a DoS.
The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Tomcat | Apache | 8.5.0 (including) | 8.5.40 (including) |
| Tomcat | Apache | 9.0.1 (including) | 9.0.19 (including) |
| Tomcat | Apache | 9.0.0-milestone1 (including) | 9.0.0-milestone1 (including) |
| Tomcat | Apache | 9.0.0-milestone10 (including) | 9.0.0-milestone10 (including) |
| Tomcat | Apache | 9.0.0-milestone11 (including) | 9.0.0-milestone11 (including) |
| Tomcat | Apache | 9.0.0-milestone12 (including) | 9.0.0-milestone12 (including) |
| Tomcat | Apache | 9.0.0-milestone13 (including) | 9.0.0-milestone13 (including) |
| Tomcat | Apache | 9.0.0-milestone14 (including) | 9.0.0-milestone14 (including) |
| Tomcat | Apache | 9.0.0-milestone15 (including) | 9.0.0-milestone15 (including) |
| Tomcat | Apache | 9.0.0-milestone16 (including) | 9.0.0-milestone16 (including) |
| Tomcat | Apache | 9.0.0-milestone17 (including) | 9.0.0-milestone17 (including) |
| Tomcat | Apache | 9.0.0-milestone18 (including) | 9.0.0-milestone18 (including) |
| Tomcat | Apache | 9.0.0-milestone19 (including) | 9.0.0-milestone19 (including) |
| Tomcat | Apache | 9.0.0-milestone2 (including) | 9.0.0-milestone2 (including) |
| Tomcat | Apache | 9.0.0-milestone20 (including) | 9.0.0-milestone20 (including) |
| Tomcat | Apache | 9.0.0-milestone21 (including) | 9.0.0-milestone21 (including) |
| Tomcat | Apache | 9.0.0-milestone22 (including) | 9.0.0-milestone22 (including) |
| Tomcat | Apache | 9.0.0-milestone23 (including) | 9.0.0-milestone23 (including) |
| Tomcat | Apache | 9.0.0-milestone24 (including) | 9.0.0-milestone24 (including) |
| Tomcat | Apache | 9.0.0-milestone25 (including) | 9.0.0-milestone25 (including) |
| Tomcat | Apache | 9.0.0-milestone26 (including) | 9.0.0-milestone26 (including) |
| Tomcat | Apache | 9.0.0-milestone27 (including) | 9.0.0-milestone27 (including) |
| Tomcat | Apache | 9.0.0-milestone3 (including) | 9.0.0-milestone3 (including) |
| Tomcat | Apache | 9.0.0-milestone4 (including) | 9.0.0-milestone4 (including) |
| Tomcat | Apache | 9.0.0-milestone5 (including) | 9.0.0-milestone5 (including) |
| Tomcat | Apache | 9.0.0-milestone6 (including) | 9.0.0-milestone6 (including) |
| Tomcat | Apache | 9.0.0-milestone7 (including) | 9.0.0-milestone7 (including) |
| Tomcat | Apache | 9.0.0-milestone8 (including) | 9.0.0-milestone8 (including) |
| Tomcat | Apache | 9.0.0-milestone9 (including) | 9.0.0-milestone9 (including) |
Locking is a type of synchronization behavior that ensures that multiple independently-operating processes or threads do not interfere with each other when accessing the same resource. All processes/threads are expected to follow the same steps for locking. If these steps are not followed precisely - or if no locking is done at all - then another process/thread could modify the shared resource in a way that is not visible or predictable to the original process. This can lead to data or memory corruption, denial of service, etc.