{"schema_version":"1.7.5","id":"CVE-2021-20181","published":"2021-05-13T16:15:07.653Z","modified":"2026-07-08T05:56:17.874289855Z","related":["SUSE-SU-2021:0521-1","SUSE-SU-2021:1240-1","SUSE-SU-2021:1241-1","SUSE-SU-2021:1242-1","SUSE-SU-2021:1244-1","SUSE-SU-2021:1245-1","SUSE-SU-2021:1305-1","SUSE-SU-2021:14704-1","SUSE-SU-2021:14706-1","openSUSE-SU-2021:0363-1","openSUSE-SU-2024:11287-1"],"details":"A race condition flaw was found in the 9pfs server implementation of QEMU up to and including 5.2.0. This flaw allows a malicious 9p client to cause a use-after-free error, potentially escalating their privileges on the system. The highest threat from this vulnerability is to confidentiality, integrity as well as system availability.","affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/qemu/qemu","events":[{"introduced":"0"},{"last_affected":"553032db17440f8de011390e5a1cfddd13751b0b"}],"database_specific":{"cpe":"cpe:2.3:a:qemu:qemu:*:*:*:*:*:*:*:*","extracted_events":[{"introduced":"0"},{"last_affected":"5.2.0"}],"source":"CPE_RANGE"}}],"versions":["v5.2.0","v5.2.0-rc4","v5.2.0-rc3","v5.2.0-rc2","v5.2.0-rc1","v5.2.0-rc0","v5.0.0","v5.1.0","v5.1.0-rc3","v5.1.0-rc2","v5.1.0-rc1","v5.1.0-rc0","v4.2.0","v5.0.0-rc4","v5.0.0-rc3","v5.0.0-rc2","v5.0.0-rc1","v5.0.0-rc0","v4.2.0-rc5","v4.2.0-rc4","v4.2.0-rc3","v4.2.0-rc2","v4.2.0-rc1","v4.2.0-rc0","v4.1.0","v4.0.0","v4.1.0-rc5","v4.1.0-rc4","v4.1.0-rc3","v4.1.0-rc2","v4.1.0-rc1","v4.1.0-rc0","v4.0.0-rc4","v4.0.0-rc3","v4.0.0-rc2","v4.0.0-rc1","v3.1.0","v4.0.0-rc0","v3.0.0","v3.1.0-rc5","v3.1.0-rc4","v3.1.0-rc3","v3.1.0-rc2","v3.1.0-rc1","v3.1.0-rc0","v3.0.0-rc4","v3.0.0-rc3","v3.0.0-rc2","v3.0.0-rc1","v3.0.0-rc0","v2.12.0","v2.12.0-rc4","v2.12.0-rc3","v2.12.0-rc2","v2.12.0-rc1","v2.12.0-rc0","v2.11.0","v2.11.0-rc5","v2.11.0-rc4","v2.11.0-rc3","v2.11.0-rc2","v2.11.0-rc1","v2.11.0-rc0","v2.10.0","v2.10.0-rc4","v2.10.0-rc3","v2.10.0-rc2","v2.10.0-rc1","v2.9.0","v2.10.0-rc0","v2.9.0-rc5","v2.9.0-rc4","v2.9.0-rc3","v2.9.0-rc2","v2.9.0-rc1","v2.8.0","v2.9.0-rc0","v2.8.0-rc4","v2.8.0-rc3","v2.8.0-rc2","v2.8.0-rc1","v2.8.0-rc0","v2.7.0","v2.7.0-rc5","v2.7.0-rc4","v2.7.0-rc3","v2.7.0-rc2","v2.6.0","v2.7.0-rc1","v2.7.0-rc0","v2.6.0-rc5","v2.6.0-rc4","v2.6.0-rc3","v2.6.0-rc2","v2.6.0-rc1","v2.6.0-rc0","v2.5.0","v2.5.0-rc4","v2.5.0-rc3","v2.5.0-rc2","v2.5.0-rc1","v2.5.0-rc0","v2.4.0","v2.4.0-rc4","v2.4.0-rc3","v2.3.0","v2.4.0-rc2","v2.4.0-rc1","v2.4.0-rc0","v2.3.0-rc4","v2.3.0-rc3","v2.3.0-rc2","v2.3.0-rc1","v2.3.0-rc0","v2.2.0","v2.2.0-rc3","v2.2.0-rc5","v2.2.0-rc4","v2.2.0-rc2","v2.2.0-rc1","v2.2.0-rc0","v2.1.0","v2.1.0-rc5","v2.1.0-rc4","v2.1.0-rc2","v2.1.0-rc3","v2.0.0","v2.1.0-rc1","v2.1.0-rc0","v2.0.0-rc3","v2.0.0-rc2","v2.0.0-rc1","v2.0.0-rc0","v1.7.0","v1.7.0-rc2","v1.7.0-rc1","v1.7.0-rc0","v1.6.0","v1.6.0-rc3","v1.6.0-rc2","v1.6.0-rc1","v1.6.0-rc0","v1.5.0","v1.5.0-rc3","v1.5.0-rc2","v1.5.0-rc1","v1.5.0-rc0","v1.4.0","v1.4.0-rc2","v1.4.0-rc1","v1.4.0-rc0","v1.3.0","v1.3.0-rc2","v1.3.0-rc1","v1.3.0-rc0","v1.2.0","v1.2.0-rc3","v1.2.0-rc2","v1.2.0-rc1","v1.2.0-rc0","v1.1.0","v1.1.0-rc4","v1.1.0-rc3","v1.1.0-rc2","v1.1-rc2","v1.1-rc1","v1.1-rc0","v1.0","v1.0-rc4","v1.0-rc3","v1.0-rc2","v1.0-rc1","v1.0-rc0","v0.14.0-rc0","v0.13.0-rc0","v0.12.0-rc0","v0.11.0-rc0","v0.5.0","v0.4.4","v0.4.3","v0.4.2","v0.4.1","v0.4.0","v0.3.0","v0.2.0","v0.1.6","v0.1.5","v0.1.4","v0.1.3","v0.1.1","v0.1.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-20181.json"}},{"ranges":[{"type":"GIT","repo":"https://gitlab.com/qemu-project/qemu","events":[{"introduced":"0"},{"last_affected":"553032db17440f8de011390e5a1cfddd13751b0b"}],"database_specific":{"cpe":"cpe:2.3:a:qemu:qemu:*:*:*:*:*:*:*:*","extracted_events":[{"introduced":"0"},{"last_affected":"5.2.0"}],"source":"CPE_RANGE"}}],"versions":["v5.2.0","v5.2.0-rc4","v5.2.0-rc3","v5.2.0-rc2","v5.2.0-rc1","v5.2.0-rc0","v5.0.0","v5.1.0","v5.1.0-rc3","v5.1.0-rc2","v5.1.0-rc1","v5.1.0-rc0","v4.2.0","v5.0.0-rc4","v5.0.0-rc3","v5.0.0-rc2","v5.0.0-rc1","v5.0.0-rc0","v4.2.0-rc5","v4.2.0-rc4","v4.2.0-rc3","v4.2.0-rc2","v4.2.0-rc1","v4.2.0-rc0","v4.1.0","v4.0.0","v4.1.0-rc5","v4.1.0-rc4","v4.1.0-rc3","v4.1.0-rc2","v4.1.0-rc1","v4.1.0-rc0","v4.0.0-rc4","v4.0.0-rc3","v4.0.0-rc2","v4.0.0-rc1","v3.1.0","v4.0.0-rc0","v3.0.0","v3.1.0-rc5","v3.1.0-rc4","v3.1.0-rc3","v3.1.0-rc2","v3.1.0-rc1","v3.1.0-rc0","v3.0.0-rc4","v3.0.0-rc3","v3.0.0-rc2","v3.0.0-rc1","v3.0.0-rc0","v2.12.0","v2.12.0-rc4","v2.12.0-rc3","v2.12.0-rc2","v2.12.0-rc1","v2.12.0-rc0","v2.11.0","v2.11.0-rc5","v2.11.0-rc4","v2.11.0-rc3","v2.11.0-rc2","v2.11.0-rc1","v2.11.0-rc0","v2.10.0","v2.10.0-rc4","v2.10.0-rc3","v2.10.0-rc2","v2.10.0-rc1","v2.9.0","v2.10.0-rc0","v2.9.0-rc5","v2.9.0-rc4","v2.9.0-rc3","v2.9.0-rc2","v2.9.0-rc1","v2.8.0","v2.9.0-rc0","v2.8.0-rc4","v2.8.0-rc3","v2.8.0-rc2","v2.8.0-rc1","v2.8.0-rc0","v2.7.0","v2.7.0-rc5","v2.7.0-rc4","v2.7.0-rc3","v2.7.0-rc2","v2.6.0","v2.7.0-rc1","v2.7.0-rc0","v2.6.0-rc5","v2.6.0-rc4","v2.6.0-rc3","v2.6.0-rc2","v2.6.0-rc1","v2.6.0-rc0","v2.5.0","v2.5.0-rc4","v2.5.0-rc3","v2.5.0-rc2","v2.5.0-rc1","v2.5.0-rc0","v2.4.0","v2.4.0-rc4","v2.4.0-rc3","v2.3.0","v2.4.0-rc2","v2.4.0-rc1","v2.4.0-rc0","v2.3.0-rc4","v2.3.0-rc3","v2.3.0-rc2","v2.3.0-rc1","v2.3.0-rc0","v2.2.0","v2.2.0-rc3","v2.2.0-rc5","v2.2.0-rc4","v2.2.0-rc2","v2.2.0-rc1","v2.2.0-rc0","v2.1.0","v2.1.0-rc5","v2.1.0-rc4","v2.1.0-rc2","v2.1.0-rc3","v2.0.0","v2.1.0-rc1","v2.1.0-rc0","v2.0.0-rc3","v2.0.0-rc2","v2.0.0-rc1","v2.0.0-rc0","v1.7.0","v1.7.0-rc2","v1.7.0-rc1","v1.7.0-rc0","v1.6.0","v1.6.0-rc3","v1.6.0-rc2","v1.6.0-rc1","v1.6.0-rc0","v1.5.0","v1.5.0-rc3","v1.5.0-rc2","v1.5.0-rc1","v1.5.0-rc0","v1.4.0","v1.4.0-rc2","v1.4.0-rc1","v1.4.0-rc0","v1.3.0",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