tomcat9 is vulnerable to remote code execution (RCE). The vulnerability exists through the incomplete fix for CVE-2020-9484, with a configuration edge case that was highly unlikely to be used.
www.openwall.com/lists/oss-security/2021/03/01/2
lists.apache.org/thread.html/r11ce01e8a4c7269b88f88212f21830edf73558997ac7744f37769b77@%3Cusers.tomcat.apache.org%3E
lists.apache.org/thread.html/r732b2ca289dc02df2de820e8775559abd6c207f159e39f559547a085@%3Cusers.tomcat.apache.org%3E
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lists.debian.org/debian-lts-announce/2021/03/msg00018.html
security-tracker.debian.org/tracker/CVE-2021-25329
security.netapp.com/advisory/ntap-20210409-0002/
www.debian.org/security/2021/dsa-4891
www.oracle.com//security-alerts/cpujul2021.html
www.oracle.com/security-alerts/cpujan2022.html
www.oracle.com/security-alerts/cpuoct2021.html