{"schema_version":"1.7.5","id":"CVE-2021-4145","published":"2022-01-25T20:15:08.657Z","modified":"2026-07-09T05:45:10.567923Z","related":["ALSA-2022:1759"],"details":"A NULL pointer dereference issue was found in the block mirror layer of QEMU in versions prior to 6.2.0. The `self` pointer is dereferenced in mirror_wait_on_conflicts() without ensuring that it's not NULL. A malicious unprivileged user within the guest could use this flaw to crash the QEMU process on the host when writing data reaches the threshold of mirroring node.","affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/qemu/qemu","events":[{"introduced":"f9baca549e44791be0dd98de15add3d8452a8af0"},{"last_affected":"ecf2706e271fa705621f0d5ad9517fe15a22bf22"}],"database_specific":{"cpe":["cpe:2.3:a:qemu:qemu:6.1.0:-:*:*:*:*:*:*","cpe:2.3:a:qemu:qemu:6.1.0:rc0:*:*:*:*:*:*","cpe:2.3:a:qemu:qemu:6.1.0:rc1:*:*:*:*:*:*","cpe:2.3:a:qemu:qemu:6.1.0:rc2:*:*:*:*:*:*","cpe:2.3:a:qemu:qemu:6.1.0:rc3:*:*:*:*:*:*","cpe:2.3:a:qemu:qemu:6.1.0:rc4:*:*:*:*:*:*"],"extracted_events":[{"introduced":"6.1.0-NA"},{"last_affected":"6.1.0-NA"},{"introduced":"6.1.0-rc0"},{"last_affected":"6.1.0-rc0"},{"introduced":"6.1.0-rc1"},{"last_affected":"6.1.0-rc1"},{"introduced":"6.1.0-rc2"},{"last_affected":"6.1.0-rc2"},{"introduced":"6.1.0-rc3"},{"last_affected":"6.1.0-rc3"},{"introduced":"6.1.0-rc4"},{"last_affected":"6.1.0-rc4"}],"source":"CPE_STRING"}}],"versions":["6.1.0-NA","6.1.0-rc0","6.1.0-rc1","6.1.0-rc2","6.1.0-rc3","6.1.0-rc4"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-4145.json"}},{"ranges":[{"type":"GIT","repo":"https://gitlab.com/qemu-project/qemu","events":[{"introduced":"f9baca549e44791be0dd98de15add3d8452a8af0"},{"last_affected":"ecf2706e271fa705621f0d5ad9517fe15a22bf22"},{"fixed":"66fed30c9cd11854fc878a4eceb507e915d7c9cd"}],"database_specific":{"cpe":["cpe:2.3:a:qemu:qemu:6.1.0:-:*:*:*:*:*:*","cpe:2.3:a:qemu:qemu:6.1.0:rc0:*:*:*:*:*:*","cpe:2.3:a:qemu:qemu:6.1.0:rc1:*:*:*:*:*:*","cpe:2.3:a:qemu:qemu:6.1.0:rc2:*:*:*:*:*:*","cpe:2.3:a:qemu:qemu:6.1.0:rc3:*:*:*:*:*:*","cpe:2.3:a:qemu:qemu:6.1.0:rc4:*:*:*:*:*:*"],"extracted_events":[{"introduced":"6.1.0-NA"},{"last_affected":"6.1.0-NA"},{"introduced":"6.1.0-rc0"},{"last_affected":"6.1.0-rc0"},{"introduced":"6.1.0-rc1"},{"last_affected":"6.1.0-rc1"},{"introduced":"6.1.0-rc2"},{"last_affected":"6.1.0-rc2"},{"introduced":"6.1.0-rc3"},{"last_affected":"6.1.0-rc3"},{"introduced":"6.1.0-rc4"},{"last_affected":"6.1.0-rc4"}],"source":["CPE_STRING","REFERENCES"]}}],"versions":["6.1.0-NA","6.1.0-rc0","6.1.0-rc1","6.1.0-rc2","6.1.0-rc3","6.1.0-rc4","v6.1.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-4145.json","vanir_signatures":[{"deprecated":false,"digest":{"function_hash":"111420676610769034413802176203666229979","length":765},"id":"CVE-2021-4145-0b3d3b8a","signature_type":"Function","signature_version":"v1","source":"https://gitlab.com/qemu-project/qemu@66fed30c9cd11854fc878a4eceb507e915d7c9cd","target":{"file":"block/mirror.c","function":"mirror_wait_on_conflicts"}},{"deprecated":false,"digest":{"line_hashes":["318922015838556192816489864438945311255","207883243228566117996208701354740977517","129441833247124108893163559685468156379","271930729929995938552906080710242646107","123116646464447836744365593482046772520","10151430632489040759507122959361894067","237221403894624056460302060588217687577","35068563641036379331739204802122430715","225885450527325332969300107213632380174"],"threshold":0.9},"id":"CVE-2021-4145-73199ac7","signature_type":"Line","signature_version":"v1","source":"https://gitlab.com/qemu-project/qemu@66fed30c9cd11854fc878a4eceb507e915d7c9cd","target":{"file":"block/mirror.c"}}],"vanir_signatures_modified":"2026-07-09T05:45:10Z"}}],"references":[{"type":"ADVISORY","url":"https://security.gentoo.org/glsa/202208-27"},{"type":"ADVISORY","url":"https://security.netapp.com/advisory/ntap-20220311-0004/"},{"type":"FIX","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2034602"},{"type":"FIX","url":"https://gitlab.com/qemu-project/qemu/-/commit/66fed30c9cd11854fc878a4eceb507e915d7c9cd"}],"database_specific":{"unresolved_ranges":[{"cpes":["cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:-:*:*:*"],"extracted_events":[{"introduced":"8.0"},{"last_affected":"8.0"}],"source":"CPE_STRING","vendor_product":"redhat:enterprise_linux"}]},"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H"}]}