What’s Vulnerable › Vulnerabilities

CVE-2021-33910

• Severity: medium (CVSS 5.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 8.8% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-07-20 · updated 2026-10-14
• Weakness: CWE-770

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.

Affected products

• Debian Linux: 10.0
• Fedoraproject Fedora: 33, 34
• NetApp Hci Management Node: all versions
• NetApp Solidfire: all versions
• systemd: before 246.15; from 247 before 247.8; from 248 before 248.5; from 249 before 249.1 — fixed in 246.15, 247.8, 248.5, 249.1

How to fix

Upgrade to a fixed version: systemd 246.15, 247.8, 248.5, 249.1. Check the vendor advisory for mitigations.

References

• http://packetstormsecurity.com/files/163621/Sequoia-A-Deep-Root-In-Linuxs-Filesystem-Layer.html
• http://www.openwall.com/lists/oss-security/2021/08/04/2
• http://www.openwall.com/lists/oss-security/2021/08/17/3
• http://www.openwall.com/lists/oss-security/2021/09/07/3
• https://cert-portal.siemens.com/productcert/pdf/ssa-222547.pdf
• https://github.com/systemd/systemd-stable/commit/4a1c5f34bd3e1daed4490e9d97918e504d19733b
• https://github.com/systemd/systemd-stable/commit/764b74113e36ac5219a4b82a05f311b5a92136ce
• https://github.com/systemd/systemd-stable/commit/b00674347337b7531c92fdb65590ab253bb57538
• https://github.com/systemd/systemd-stable/commit/cfd14c65374027b34dbbc4f0551456c5dc2d1f61
• https://github.com/systemd/systemd/commit/b34a4f0e6729de292cb3b0c03c1d48f246ad896b
• https://github.com/systemd/systemd/pull/20256/commits/441e0115646d54f080e5c3bb0ba477c892861ab9
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2LSDMHAKI4LGFOCSPXNVVSEWQFAVFWR7/

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