CVE-2021-25329

The fix for CVE-2020-9484 was incomplete. When using Apache Tomcat 10.0.0-M1 to 10.0.0, 9.0.0.M1 to 9.0.41, 8.5.0 to 8.5.61 or 7.0.0. to 7.0.107 with a configuration edge case that was highly unlikely to be used, the Tomcat instance was still vulnerable to CVE-2020-9494. Note that both the previously published prerequisites for CVE-2020-9484 and the previously published mitigations for CVE-2020-9484 also apply to this issue.

In Red Hat Enterprise Linux 8, Red Hat Certificate System 10 and Identity Management are using the pki-servlet-engine component, which embeds a vulnerable version of Tomcat. However, in these specific contexts, the prerequisites to the vulnerability are not met. The PersistentManager is not set, and a SecurityManager is used. The use of pki-servlet-engine outside of these contexts is not supported. As a result, the vulnerability can not be triggered in supported configurations of these products.

Red Hat OpenStack Platform's OpenDaylight will not be updated for this flaw because it was deprecated as of OpenStack Platform 14 and is only receiving security fixes for Important and Critical flaws.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Users may configure the PersistenceManager with an appropriate value for sessionAttributeValueClassNameFilter to ensure that only application provided attributes are serialized and deserialized. For more details about the configuration, refer to the Apache Tomcat 9 Configuration Reference https://tomcat.apache.org/tomcat-9.0-doc/config/manager.html.