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Vulnerability record · CVE-2021-33910 · published 20 July 2021

CVE-2021-33910: Systemd project systemd allocation without limits vulnerability

Systemd Project · Systemd

basic/unit-name.c in systemd prior to 246.15, 247.8, 248.5, and 249.1 has a Memory Allocation with an Excessive Size Value (involving strdupa and alloca for a pathname controlled by a local attacker) that results in an operating system crash.

5.5 CVSS 3.1 Medium EPSS 8.8% · top 5.0% CWE-770 · Allocation without limits
5.5CVSS 3.1 base score, v2 4.9
8.8%EPSS exploitation probability, 30 days
NoNot in CISA KEV
5Affected product versions listed by NVD
34References, 4 tagged exploit
17 Jun 2026Last modified by NVD

Description

basic/unit-name.c in systemd prior to 246.15, 247.8, 248.5, and 249.1 has a Memory Allocation with an Excessive Size Value (involving strdupa and alloca for a pathname controlled by a local attacker) that results in an operating system crash.

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

5 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
http://packetstormsecurity.com/files/163621/Sequoia-A-Deep-Root-In-Linuxs-Filesystem-Layer.html ExploitThird Party AdvisoryVDB Entry
http://www.openwall.com/lists/oss-security/2021/08/04/2 Mailing ListPatchThird Party Advisory
http://www.openwall.com/lists/oss-security/2021/08/17/3 Mailing ListPatchThird Party Advisory
http://www.openwall.com/lists/oss-security/2021/09/07/3 Mailing ListPatchThird Party Advisory
https://cert-portal.siemens.com/productcert/pdf/ssa-222547.pdf
https://github.com/systemd/systemd-stable/commit/4a1c5f34bd3e1daed4490e9d97918e504d19733b PatchThird Party Advisory
https://github.com/systemd/systemd-stable/commit/764b74113e36ac5219a4b82a05f311b5a92136ce PatchThird Party Advisory
https://github.com/systemd/systemd-stable/commit/b00674347337b7531c92fdb65590ab253bb57538 PatchThird Party Advisory
https://github.com/systemd/systemd-stable/commit/cfd14c65374027b34dbbc4f0551456c5dc2d1f61 PatchThird Party Advisory
https://github.com/systemd/systemd/commit/b34a4f0e6729de292cb3b0c03c1d48f246ad896b PatchThird Party Advisory
https://github.com/systemd/systemd/pull/20256/commits/441e0115646d54f080e5c3bb0ba477c892861ab9 PatchThird Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2LSDMHAKI4LGFOCSPXNVVSE
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/42TMJVNYRY65B4QCJICBYOE
https://security.gentoo.org/glsa/202107-48 Third Party Advisory
https://security.netapp.com/advisory/ntap-20211104-0008/ Third Party Advisory
https://www.debian.org/security/2021/dsa-4942 Third Party Advisory
https://www.openwall.com/lists/oss-security/2021/07/20/2 ExploitMailing ListThird Party Advisory
http://packetstormsecurity.com/files/163621/Sequoia-A-Deep-Root-In-Linuxs-Filesystem-Layer.html ExploitThird Party AdvisoryVDB Entry
http://www.openwall.com/lists/oss-security/2021/08/04/2 Mailing ListPatchThird Party Advisory
http://www.openwall.com/lists/oss-security/2021/08/17/3 Mailing ListPatchThird Party Advisory
http://www.openwall.com/lists/oss-security/2021/09/07/3 Mailing ListPatchThird Party Advisory
https://cert-portal.siemens.com/productcert/pdf/ssa-222547.pdf
https://github.com/systemd/systemd-stable/commit/4a1c5f34bd3e1daed4490e9d97918e504d19733b PatchThird Party Advisory
https://github.com/systemd/systemd-stable/commit/764b74113e36ac5219a4b82a05f311b5a92136ce PatchThird Party Advisory
https://github.com/systemd/systemd-stable/commit/b00674347337b7531c92fdb65590ab253bb57538 PatchThird Party Advisory
https://github.com/systemd/systemd-stable/commit/cfd14c65374027b34dbbc4f0551456c5dc2d1f61 PatchThird Party Advisory
https://github.com/systemd/systemd/commit/b34a4f0e6729de292cb3b0c03c1d48f246ad896b PatchThird Party Advisory
https://github.com/systemd/systemd/pull/20256/commits/441e0115646d54f080e5c3bb0ba477c892861ab9 PatchThird Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2LSDMHAKI4LGFOCSPXNVVSE
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/42TMJVNYRY65B4QCJICBYOE
https://security.gentoo.org/glsa/202107-48 Third Party Advisory
https://security.netapp.com/advisory/ntap-20211104-0008/ Third Party Advisory
https://www.debian.org/security/2021/dsa-4942 Third Party Advisory
https://www.openwall.com/lists/oss-security/2021/07/20/2 ExploitMailing ListThird Party Advisory

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Source: NIST National Vulnerability Database (record CVE-2021-33910), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.