{"id":"CVE-2020-9484","url":"https://www.cyber-defence.io/tools/cve/CVE-2020-9484","generatedAt":"2026-11-05T02:12:45.514Z","title":"When using Apache Tomcat versions 10.0.0-M1 to 10.0.0-M4, 9.0.0.M1 to 9.0.34, 8.5.0 to 8.5.54 and 7.0.0 to 7.0.103 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…","description":"When using Apache Tomcat versions 10.0.0-M1 to 10.0.0-M4, 9.0.0.M1 to 9.0.34, 8.5.0 to 8.5.54 and 7.0.0 to 7.0.103 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.","published":"2020-05-20T19:15:09.000Z","lastModified":"2026-10-08T21:17:33.000Z","status":"Modified","sourceIdentifier":"security@apache.org","cvss":{"version":"3.1","score":7,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-502"],"affected":["apache/tomcat","debian/debian linux","opensuse/leap","fedoraproject/fedora","canonical/ubuntu linux","oracle/agile engineering data management","oracle/agile product lifecycle management","oracle/communications cloud native core binding support function","oracle/communications cloud native core policy","oracle/communications diameter signaling router","oracle/communications element manager","oracle/communications instant messaging server","oracle/communications session report manager","oracle/communications session route manager","oracle/database","oracle/fmw platform","oracle/hospitality guest access","oracle/instantis enterprisetrack","oracle/managed file transfer","oracle/mysql enterprise monitor","oracle/retail order broker","oracle/siebel apps - marketing","oracle/siebel ui framework","oracle/transportation management","oracle/workload manager","mcafee/epolicy orchestrator"],"epss":{"score":0.5552,"percentile":0.99037,"date":"2026-11-03","history":[{"date":"2026-09-24","score":0.5552,"percentile":0.99004}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"urgent","text":"EPSS puts the probability of exploitation in the next 30 days at 55.5%, higher than 99% of all known CVEs. Patch or mitigate before the next change window."},"changes":[],"references":[{"url":"http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00057.html","tags":["Third Party Advisory"],"source":"security@apache.org"},{"url":"http://packetstormsecurity.com/files/157924/Apache-Tomcat-CVE-2020-9484-Proof-Of-Concept.html","tags":["Third Party Advisory","VDB Entry"],"source":"security@apache.org"},{"url":"http://seclists.org/fulldisclosure/2020/Jun/6","tags":["Mailing List","Third Party Advisory"],"source":"security@apache.org"},{"url":"http://www.openwall.com/lists/oss-security/2021/03/01/2","tags":["Mailing List","Third Party Advisory"],"source":"security@apache.org"},{"url":"https://kc.mcafee.com/corporate/index?page=content&id=SB10332","tags":["Third Party 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BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}