5.5
MEDIUM
CVE-2021-33910
Systemd Memory Allocation Excessive Size Crash
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.

INFO

Published Date :

July 20, 2021, 7:15 p.m.

Last Modified :

June 9, 2025, 4:15 p.m.

Source :

[email protected]

Remotely Exploitable :

No

Impact Score :

3.6

Exploitability Score :

1.8
Public PoC/Exploit Available at Github

CVE-2021-33910 has a 1 public PoC/Exploit available at Github. Go to the Public Exploits tab to see the list.

Affected Products

The following products are affected by CVE-2021-33910 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Netapp hci_management_node
2 Netapp solidfire
1 Fedoraproject fedora
1 Debian debian_linux
1 Systemd_project systemd
1 Siemens scalance_lpe9403_firmware
: Total Affected Vendor : 5 | Products : 6
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2021-33910.

URL Resource
http://packetstormsecurity.com/files/163621/Sequoia-A-Deep-Root-In-Linuxs-Filesystem-Layer.html Exploit Third Party Advisory VDB Entry
http://www.openwall.com/lists/oss-security/2021/08/04/2 Mailing List Patch Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/08/17/3 Mailing List Patch Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/09/07/3 Mailing List Patch Third Party Advisory
https://cert-portal.siemens.com/productcert/pdf/ssa-222547.pdf
https://github.com/systemd/systemd-stable/commit/4a1c5f34bd3e1daed4490e9d97918e504d19733b Patch Third Party Advisory
https://github.com/systemd/systemd-stable/commit/764b74113e36ac5219a4b82a05f311b5a92136ce Patch Third Party Advisory
https://github.com/systemd/systemd-stable/commit/b00674347337b7531c92fdb65590ab253bb57538 Patch Third Party Advisory
https://github.com/systemd/systemd-stable/commit/cfd14c65374027b34dbbc4f0551456c5dc2d1f61 Patch Third Party Advisory
https://github.com/systemd/systemd/commit/b34a4f0e6729de292cb3b0c03c1d48f246ad896b Patch Third Party Advisory
https://github.com/systemd/systemd/pull/20256/commits/441e0115646d54f080e5c3bb0ba477c892861ab9 Patch Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2LSDMHAKI4LGFOCSPXNVVSEWQFAVFWR7/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/42TMJVNYRY65B4QCJICBYOEIVZV3KUYI/
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 Exploit Mailing List Third Party Advisory
http://packetstormsecurity.com/files/163621/Sequoia-A-Deep-Root-In-Linuxs-Filesystem-Layer.html Exploit Third Party Advisory VDB Entry
http://www.openwall.com/lists/oss-security/2021/08/04/2 Mailing List Patch Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/08/17/3 Mailing List Patch Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/09/07/3 Mailing List Patch Third Party Advisory
https://cert-portal.siemens.com/productcert/pdf/ssa-222547.pdf
https://github.com/systemd/systemd-stable/commit/4a1c5f34bd3e1daed4490e9d97918e504d19733b Patch Third Party Advisory
https://github.com/systemd/systemd-stable/commit/764b74113e36ac5219a4b82a05f311b5a92136ce Patch Third Party Advisory
https://github.com/systemd/systemd-stable/commit/b00674347337b7531c92fdb65590ab253bb57538 Patch Third Party Advisory
https://github.com/systemd/systemd-stable/commit/cfd14c65374027b34dbbc4f0551456c5dc2d1f61 Patch Third Party Advisory
https://github.com/systemd/systemd/commit/b34a4f0e6729de292cb3b0c03c1d48f246ad896b Patch Third Party Advisory
https://github.com/systemd/systemd/pull/20256/commits/441e0115646d54f080e5c3bb0ba477c892861ab9 Patch Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2LSDMHAKI4LGFOCSPXNVVSEWQFAVFWR7/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/42TMJVNYRY65B4QCJICBYOEIVZV3KUYI/
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 Exploit Mailing List Third Party Advisory

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

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Updated: 2 years, 4 months ago
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Born at : March 10, 2023, 5:24 p.m. This repo has been linked 1 different CVEs too.

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2021-33910 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2021-33910 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jun. 09, 2025

    Action Type Old Value New Value
    Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
    Added CWE CWE-770
  • CVE Modified by af854a3a-2127-422b-91ae-364da2661108

    Nov. 21, 2024

    Action Type Old Value New Value
    Added Reference http://packetstormsecurity.com/files/163621/Sequoia-A-Deep-Root-In-Linuxs-Filesystem-Layer.html
    Added Reference http://www.openwall.com/lists/oss-security/2021/08/04/2
    Added Reference http://www.openwall.com/lists/oss-security/2021/08/17/3
    Added Reference http://www.openwall.com/lists/oss-security/2021/09/07/3
    Added Reference https://cert-portal.siemens.com/productcert/pdf/ssa-222547.pdf
    Added Reference https://github.com/systemd/systemd/commit/b34a4f0e6729de292cb3b0c03c1d48f246ad896b
    Added Reference https://github.com/systemd/systemd/pull/20256/commits/441e0115646d54f080e5c3bb0ba477c892861ab9
    Added Reference https://github.com/systemd/systemd-stable/commit/4a1c5f34bd3e1daed4490e9d97918e504d19733b
    Added Reference https://github.com/systemd/systemd-stable/commit/764b74113e36ac5219a4b82a05f311b5a92136ce
    Added Reference https://github.com/systemd/systemd-stable/commit/b00674347337b7531c92fdb65590ab253bb57538
    Added Reference https://github.com/systemd/systemd-stable/commit/cfd14c65374027b34dbbc4f0551456c5dc2d1f61
    Added Reference https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2LSDMHAKI4LGFOCSPXNVVSEWQFAVFWR7/
    Added Reference https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/42TMJVNYRY65B4QCJICBYOEIVZV3KUYI/
    Added Reference https://security.gentoo.org/glsa/202107-48
    Added Reference https://security.netapp.com/advisory/ntap-20211104-0008/
    Added Reference https://www.debian.org/security/2021/dsa-4942
    Added Reference https://www.openwall.com/lists/oss-security/2021/07/20/2
  • CVE Modified by [email protected]

    May. 14, 2024

    Action Type Old Value New Value
  • CVE Modified by [email protected]

    Nov. 07, 2023

    Action Type Old Value New Value
    Added Reference MITRE https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2LSDMHAKI4LGFOCSPXNVVSEWQFAVFWR7/ [No types assigned]
    Added Reference MITRE https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/42TMJVNYRY65B4QCJICBYOEIVZV3KUYI/ [No types assigned]
    Removed Reference MITRE https://lists.fedoraproject.org/archives/list/[email protected]/message/2LSDMHAKI4LGFOCSPXNVVSEWQFAVFWR7/
    Removed Reference MITRE https://lists.fedoraproject.org/archives/list/[email protected]/message/42TMJVNYRY65B4QCJICBYOEIVZV3KUYI/
  • CVE Modified by [email protected]

    Jun. 14, 2022

    Action Type Old Value New Value
    Added Reference https://cert-portal.siemens.com/productcert/pdf/ssa-222547.pdf [No Types Assigned]
  • Reanalysis by [email protected]

    Jan. 28, 2022

    Action Type Old Value New Value
    Changed CPE Configuration OR *cpe:2.3:a:freedesktop:systemd:*:*:*:*:*:*:*:* versions up to (excluding) 246.15 *cpe:2.3:a:freedesktop:systemd:*:*:*:*:*:*:*:* versions from (including) 248 up to (excluding) 248.5 *cpe:2.3:a:freedesktop:systemd:*:*:*:*:*:*:*:* versions from (including) 249 up to (excluding) 249.1 *cpe:2.3:a:systemd_project:systemd:*:*:*:*:*:*:*:* versions from (including) 247 up to (excluding) 247.8 OR *cpe:2.3:a:systemd_project:systemd:*:*:*:*:*:*:*:* versions up to (excluding) 246.15 *cpe:2.3:a:systemd_project:systemd:*:*:*:*:*:*:*:* versions from (including) 247 up to (excluding) 247.8 *cpe:2.3:a:systemd_project:systemd:*:*:*:*:*:*:*:* versions from (including) 248 up to (excluding) 248.5 *cpe:2.3:a:systemd_project:systemd:*:*:*:*:*:*:*:* versions from (including) 249 up to (excluding) 249.1
  • CPE Deprecation Remap by [email protected]

    Jan. 28, 2022

    Action Type Old Value New Value
    Changed CPE Configuration OR *cpe:2.3:a:freedesktop:systemd:*:*:*:*:*:*:*:* versions from (including) 247 from (excluding) 247.8 OR *cpe:2.3:a:systemd_project:systemd:*:*:*:*:*:*:*:* versions from (including) 247 from (excluding) 247.8
  • Modified Analysis by [email protected]

    Nov. 23, 2021

    Action Type Old Value New Value
    Changed Reference Type http://www.openwall.com/lists/oss-security/2021/08/04/2 Mailing List, Third Party Advisory http://www.openwall.com/lists/oss-security/2021/08/04/2 Mailing List, Patch, Third Party Advisory
    Changed Reference Type http://www.openwall.com/lists/oss-security/2021/08/17/3 Mailing List, Third Party Advisory http://www.openwall.com/lists/oss-security/2021/08/17/3 Mailing List, Patch, Third Party Advisory
    Changed Reference Type http://www.openwall.com/lists/oss-security/2021/09/07/3 Mailing List, Third Party Advisory http://www.openwall.com/lists/oss-security/2021/09/07/3 Mailing List, Patch, Third Party Advisory
    Changed Reference Type https://security.netapp.com/advisory/ntap-20211104-0008/ No Types Assigned https://security.netapp.com/advisory/ntap-20211104-0008/ Third Party Advisory
    Added CPE Configuration OR *cpe:2.3:a:netapp:hci_management_node:-:*:*:*:*:*:*:* *cpe:2.3:a:netapp:solidfire:-:*:*:*:*:*:*:*
  • CVE Modified by [email protected]

    Nov. 17, 2021

    Action Type Old Value New Value
    Added Reference https://security.netapp.com/advisory/ntap-20211104-0008/ [No Types Assigned]
  • CVE Modified by [email protected]

    Nov. 10, 2021

    Action Type Old Value New Value
    Removed Reference https://security.netapp.com/advisory/ntap-20211104-0008/ [No Types Assigned]
  • CVE Modified by [email protected]

    Nov. 04, 2021

    Action Type Old Value New Value
    Added Reference https://security.netapp.com/advisory/ntap-20211104-0008/ [No Types Assigned]
  • Modified Analysis by [email protected]

    Sep. 21, 2021

    Action Type Old Value New Value
    Changed Reference Type http://www.openwall.com/lists/oss-security/2021/08/04/2 No Types Assigned http://www.openwall.com/lists/oss-security/2021/08/04/2 Mailing List, Third Party Advisory
    Changed Reference Type http://www.openwall.com/lists/oss-security/2021/08/17/3 No Types Assigned http://www.openwall.com/lists/oss-security/2021/08/17/3 Mailing List, Third Party Advisory
    Changed Reference Type http://www.openwall.com/lists/oss-security/2021/09/07/3 No Types Assigned http://www.openwall.com/lists/oss-security/2021/09/07/3 Mailing List, Third Party Advisory
  • CVE Modified by [email protected]

    Sep. 07, 2021

    Action Type Old Value New Value
    Added Reference http://www.openwall.com/lists/oss-security/2021/09/07/3 [No Types Assigned]
  • CVE Modified by [email protected]

    Aug. 17, 2021

    Action Type Old Value New Value
    Added Reference http://www.openwall.com/lists/oss-security/2021/08/17/3 [No Types Assigned]
  • CVE Modified by [email protected]

    Aug. 04, 2021

    Action Type Old Value New Value
    Added Reference http://www.openwall.com/lists/oss-security/2021/08/04/2 [No Types Assigned]
  • Initial Analysis by [email protected]

    Jul. 29, 2021

    Action Type Old Value New Value
    Added CVSS V2 NIST (AV:L/AC:L/Au:N/C:N/I:N/A:C)
    Added CVSS V3.1 NIST AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
    Changed Reference Type http://packetstormsecurity.com/files/163621/Sequoia-A-Deep-Root-In-Linuxs-Filesystem-Layer.html No Types Assigned http://packetstormsecurity.com/files/163621/Sequoia-A-Deep-Root-In-Linuxs-Filesystem-Layer.html Exploit, Third Party Advisory, VDB Entry
    Changed Reference Type https://github.com/systemd/systemd/commit/b34a4f0e6729de292cb3b0c03c1d48f246ad896b No Types Assigned https://github.com/systemd/systemd/commit/b34a4f0e6729de292cb3b0c03c1d48f246ad896b Patch, Third Party Advisory
    Changed Reference Type https://github.com/systemd/systemd/pull/20256/commits/441e0115646d54f080e5c3bb0ba477c892861ab9 No Types Assigned https://github.com/systemd/systemd/pull/20256/commits/441e0115646d54f080e5c3bb0ba477c892861ab9 Patch, Third Party Advisory
    Changed Reference Type https://github.com/systemd/systemd-stable/commit/4a1c5f34bd3e1daed4490e9d97918e504d19733b No Types Assigned https://github.com/systemd/systemd-stable/commit/4a1c5f34bd3e1daed4490e9d97918e504d19733b Patch, Third Party Advisory
    Changed Reference Type https://github.com/systemd/systemd-stable/commit/764b74113e36ac5219a4b82a05f311b5a92136ce No Types Assigned https://github.com/systemd/systemd-stable/commit/764b74113e36ac5219a4b82a05f311b5a92136ce Patch, Third Party Advisory
    Changed Reference Type https://github.com/systemd/systemd-stable/commit/b00674347337b7531c92fdb65590ab253bb57538 No Types Assigned https://github.com/systemd/systemd-stable/commit/b00674347337b7531c92fdb65590ab253bb57538 Patch, Third Party Advisory
    Changed Reference Type https://github.com/systemd/systemd-stable/commit/cfd14c65374027b34dbbc4f0551456c5dc2d1f61 No Types Assigned https://github.com/systemd/systemd-stable/commit/cfd14c65374027b34dbbc4f0551456c5dc2d1f61 Patch, Third Party Advisory
    Changed Reference Type https://lists.fedoraproject.org/archives/list/[email protected]/message/2LSDMHAKI4LGFOCSPXNVVSEWQFAVFWR7/ No Types Assigned https://lists.fedoraproject.org/archives/list/[email protected]/message/2LSDMHAKI4LGFOCSPXNVVSEWQFAVFWR7/ Mailing List, Third Party Advisory
    Changed Reference Type https://lists.fedoraproject.org/archives/list/[email protected]/message/42TMJVNYRY65B4QCJICBYOEIVZV3KUYI/ No Types Assigned https://lists.fedoraproject.org/archives/list/[email protected]/message/42TMJVNYRY65B4QCJICBYOEIVZV3KUYI/ Mailing List, Third Party Advisory
    Changed Reference Type https://security.gentoo.org/glsa/202107-48 No Types Assigned https://security.gentoo.org/glsa/202107-48 Third Party Advisory
    Changed Reference Type https://www.debian.org/security/2021/dsa-4942 No Types Assigned https://www.debian.org/security/2021/dsa-4942 Third Party Advisory
    Changed Reference Type https://www.openwall.com/lists/oss-security/2021/07/20/2 No Types Assigned https://www.openwall.com/lists/oss-security/2021/07/20/2 Exploit, Mailing List, Third Party Advisory
    Added CWE NIST CWE-770
    Added CPE Configuration OR *cpe:2.3:a:freedesktop:systemd:*:*:*:*:*:*:*:* versions up to (excluding) 246.15 *cpe:2.3:a:freedesktop:systemd:*:*:*:*:*:*:*:* versions from (including) 247 up to (excluding) 247.8 *cpe:2.3:a:freedesktop:systemd:*:*:*:*:*:*:*:* versions from (including) 248 up to (excluding) 248.5 *cpe:2.3:a:freedesktop:systemd:*:*:*:*:*:*:*:* versions from (including) 249 up to (excluding) 249.1
    Added CPE Configuration OR *cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:* *cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*
    Added CPE Configuration OR *cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
  • CVE Modified by [email protected]

    Jul. 24, 2021

    Action Type Old Value New Value
    Added Reference https://lists.fedoraproject.org/archives/list/[email protected]/message/42TMJVNYRY65B4QCJICBYOEIVZV3KUYI/ [No Types Assigned]
  • CVE Modified by [email protected]

    Jul. 22, 2021

    Action Type Old Value New Value
    Changed Description basic/unit-name.c in systemd 220 through 248 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. 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.
    Removed Reference https://github.com/systemd/systemd/releases [No Types Assigned]
    Added Reference https://github.com/systemd/systemd-stable/commit/764b74113e36ac5219a4b82a05f311b5a92136ce [No Types Assigned]
    Added Reference https://github.com/systemd/systemd-stable/commit/4a1c5f34bd3e1daed4490e9d97918e504d19733b [No Types Assigned]
    Added Reference https://lists.fedoraproject.org/archives/list/[email protected]/message/2LSDMHAKI4LGFOCSPXNVVSEWQFAVFWR7/ [No Types Assigned]
    Added Reference https://github.com/systemd/systemd-stable/commit/b00674347337b7531c92fdb65590ab253bb57538 [No Types Assigned]
    Added Reference https://github.com/systemd/systemd/commit/b34a4f0e6729de292cb3b0c03c1d48f246ad896b [No Types Assigned]
    Added Reference https://github.com/systemd/systemd-stable/commit/cfd14c65374027b34dbbc4f0551456c5dc2d1f61 [No Types Assigned]
  • CVE Modified by [email protected]

    Jul. 21, 2021

    Action Type Old Value New Value
    Added Reference http://packetstormsecurity.com/files/163621/Sequoia-A-Deep-Root-In-Linuxs-Filesystem-Layer.html [No Types Assigned]
  • CVE Modified by [email protected]

    Jul. 21, 2021

    Action Type Old Value New Value
    Added Reference https://www.debian.org/security/2021/dsa-4942 [No Types Assigned]
  • CVE Modified by [email protected]

    Jul. 20, 2021

    Action Type Old Value New Value
    Added Reference https://security.gentoo.org/glsa/202107-48 [No Types Assigned]
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2021-33910 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2021-33910 weaknesses.

CAPEC-125: Flooding Flooding CAPEC-130: Excessive Allocation Excessive Allocation CAPEC-147: XML Ping of the Death XML Ping of the Death CAPEC-197: Exponential Data Expansion Exponential Data Expansion CAPEC-229: Serialized Data Parameter Blowup Serialized Data Parameter Blowup CAPEC-230: Serialized Data with Nested Payloads Serialized Data with Nested Payloads CAPEC-231: Oversized Serialized Data Payloads Oversized Serialized Data Payloads CAPEC-469: HTTP DoS HTTP DoS CAPEC-482: TCP Flood TCP Flood CAPEC-486: UDP Flood UDP Flood CAPEC-487: ICMP Flood ICMP Flood CAPEC-488: HTTP Flood HTTP Flood CAPEC-489: SSL Flood SSL Flood CAPEC-490: Amplification Amplification CAPEC-491: Quadratic Data Expansion Quadratic Data Expansion CAPEC-493: SOAP Array Blowup SOAP Array Blowup CAPEC-494: TCP Fragmentation TCP Fragmentation CAPEC-495: UDP Fragmentation UDP Fragmentation CAPEC-496: ICMP Fragmentation ICMP Fragmentation CAPEC-528: XML Flood XML Flood
Exploit Prediction

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.

0.09 }} -0.02%

score

0.27253

percentile

CVSS31 - Vulnerability Scoring System
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability
: