21 May 2020
Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2020.1793 Apache Tomcat Remote Code Execution vulnerability 21 May 2020 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: tomcat Publisher: Apache Operating System: Windows UNIX variants (UNIX, Linux, OSX) Impact/Access: Execute Arbitrary Code/Commands -- Existing Account Resolution: Patch/Upgrade CVE Names: CVE-2020-9484 Original Bulletin: https://email@example.com/msg135215.html - --------------------------BEGIN INCLUDED TEXT-------------------- CVE-2020-9484 Apache Tomcat Remote Code Execution via session persistence Severity: High Vendor: The Apache Software Foundation Versions Affected: Apache Tomcat 10.0.0-M1 to 10.0.0-M4 Apache Tomcat 9.0.0.M1 to 9.0.34 Apache Tomcat 8.5.0 to 8.5.54 Apache Tomcat 7.0.0 to 7.0.103 Description: If: a) an attacker is able to control the contents and name of a file on the server; and b) the server is configured to use the PersistenceManager with a FileStore; and c) the PersistenceManager is configured with sessionAttributeValueClassNameFilter="null" (the default unless a SecurityManager is used) or a sufficiently lax filter to allow the attacker provided object to be deserialized; and d) the attacker knows the relative file path from the storage location used by FileStore to the file the attacker has control over; then, using a specifically crafted request, the attacker will be able to trigger remote code execution via deserialization of the file under their control. Note that all of conditions a) to d) must be true for the attack to succeed. Mitigation: - - Upgrade to Apache Tomcat 10.0.0-M5 or later - - Upgrade to Apache Tomcat 9.0.35 or later - - Upgrade to Apache Tomcat 8.5.55 or later - - Upgrade to Apache Tomcat 7.0.104 or later Alternatively, users may configure the PersistenceManager with an appropriate value for sessionAttributeValueClassNameFilter to ensure that only application provided attributes are serialized and deserialized. Credit: This issue was discovered and reported responsibly to the Apache Tomcat Security Team by report by jarvis threedr3am of pdd security research References:  http://tomcat.apache.org/security-10.html  http://tomcat.apache.org/security-9.html  http://tomcat.apache.org/security-8.html  http://tomcat.apache.org/security-7.html - --------------------------END INCLUDED TEXT-------------------- You have received this e-mail bulletin as a result of your organisation's registration with AusCERT. The mailing list you are subscribed to is maintained within your organisation, so if you do not wish to continue receiving these bulletins you should contact your local IT manager. If you do not know who that is, please send an email to firstname.lastname@example.org and we will forward your request to the appropriate person. NOTE: Third Party Rights This security bulletin is provided as a service to AusCERT's members. As AusCERT did not write the document quoted above, AusCERT has had no control over its content. The decision to follow or act on information or advice contained in this security bulletin is the responsibility of each user or organisation, and should be considered in accordance with your organisation's site policies and procedures. AusCERT takes no responsibility for consequences which may arise from following or acting on information or advice contained in this security bulletin. NOTE: This is only the original release of the security bulletin. It may not be updated when updates to the original are made. If downloading at a later date, it is recommended that the bulletin is retrieved directly from the author's website to ensure that the information is still current. Contact information for the authors of the original document is included in the Security Bulletin above. If you have any questions or need further information, please contact them directly. Previous advisories and external security bulletins can be retrieved from: https://www.auscert.org.au/bulletins/ =========================================================================== Australian Computer Emergency Response Team The University of Queensland Brisbane Qld 4072 Internet Email: email@example.com Facsimile: (07) 3365 7031 Telephone: (07) 3365 4417 (International: +61 7 3365 4417) AusCERT personnel answer during Queensland business hours which are GMT+10:00 (AEST). On call after hours for member emergencies only. =========================================================================== -----BEGIN PGP SIGNATURE----- Comment: http://www.auscert.org.au/render.html?it=1967 iQIVAwUBXsW9ueNLKJtyKPYoAQjshxAAiCRwD4q6kdJ1VnZ8DwveoE529ocKJOA3 fBjVtLLVQ769bBdX0lqkboB3zhg/44ICWAub3dhu8ArnAFeFmCO+jQcKHdZIOjWp E6q3yX07c4EcuJ2u+t7xzbCumQvf77mVU6Gu49DaPcZjgt3lUCYRM0gHqDHc12Gc oO9eXbT6lMlONYP3GqvicR5hKpdOJ693MgJoONUpf3R6LnxaB1ENZ3k7Dw/01RO4 rP9m3Cy0oeeVzpl7qKkCz6T8m+5qUsb1AJWcRLix5Y1i1hCCaaJt/yxzsZCMtu6e O8OutFUmvUkubJ5GPsDaMPJmt5890n0Yhz54NikAplHEa8pU+P9Oe42Y+oIewSWh TADbIPvZ81Uw0wIm48fm48ge8Li1yiW+BN3Pb5GoSB90goHMK/veDUXjZNDD5lIT 4wcM41lQfaIlRb8wVsaDRh876j41MWKA6IUYmibg+2PZgjxpC4q22960trlbBcMv VR+OkNX8m90bPVVvAtKSMrIw4yti5chyovKZ4UzD+b4JjZ/QEb6A+A/m2eddTrK2 dhnsKqkXgNSNxy3/4AytU2jAsukNOlSZzJDsX7h6VrK16wfcyLmVibdBwBkw+/ZJ ePKazPn2Y711dhUrEAwTg7j7VJJ8jz9456QWQmkEeKrIvmrH8EBCn1d6GrBkKRG6 horCQK0YeYQ= =2qTO -----END PGP SIGNATURE-----