Home/CVE/A flaw was found in systemd. An uncontrolled recursion in systemd-tmpfiles may lead to a denial of service at boot time
CVE

CVE-2021-3997

A flaw was found in systemd. An uncontrolled recursion in systemd-tmpfiles may lead to a denial of service at boot time

A flaw was found in systemd. An uncontrolled recursion in systemd-tmpfiles may lead to a denial of service at boot time when too many nested directories are created in /tmp.

MEDIUM · CVSS 5.5 EPSS 0.00023
Monitor
  • No active-exploitation, high-EPSS, or public-exploit signals - routine patching cadence
Sigma rules1 YARA rules0
⬡

Weakness Classification

CWE-674Uncontrolled Recursion
CWE-674Uncontrolled Recursion
▤

Affected Products & Versions

3
systemd project systemd>= 240 and < 250.2
fedoraproject fedoraall versions
redhat enterprise linuxall versions
◈

Sigma Hunt Rules

1
Exact rules name this CVE ID. Product rules name an affected product in their title. Related rules cover techniques used by actors who exploited this CVE. Showing the most relevant matches; the complete related set is on the full drill-down.
productmediumSystemd Service Creation
▣

Scoring & Timeline

5.5
MEDIUM · CVSS v3.1 · secalert@redhat.com
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD23 Aug 2022 · 08:15 PM
CVSS VectorCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
⚑

Vendor Advisories

9
suse-csafopenSUSE-SU-2024:11731-1
siemens-csafSSA-398330
msrcCVE-2021-3997
suse-csafopenSUSE-SU-2022:0539-1
suse-csafSUSE-SU-2022:0539-1
🔗

References & Sources

5
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://access.redhat.com/security/cve/CVE-2021-3997Issue TrackingThird Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2024639Issue TrackingPatchThird Party Advisory
https://github.com/systemd/systemd/commit/5b1cf7a9be37e20133c0208005274ce4a5b5c6a1PatchThird Party Advisory
https://security.gentoo.org/glsa/202305-15
https://www.openwall.com/lists/oss-security/2022/01/10/2ExploitMailing ListThird Party Advisory
Intelligence Graph · click any node to traverse
CVETechnique ActorTool Family
drag to reposition · click any node to traverse · button top-right enlarges
External lookups - second-class, for what we don’t hold ourselves
NVDCVE.orgCISAVulnersExploit-DBGitHub PoCVulnCheck KEVGreyNoise
Vulnerabilities
CISA KEV catalog
CWE weaknesses
CAPEC attack patterns
Package vulnerabilities
Threat intelligence
Threat actors
Tools & malware
ATT&CK techniques
IOCs
Detection & defense
Sigma rules
YARA rules
Atomic Red Team tests
D3FEND countermeasures
Compliance
NIST 800-53
ISO 27001:2022
SOC 2 TSC
PCI-DSS v4.0
CIS Controls v8.1
About
All capabilities
Live statistics
Data sources
Privacy policy
Terms of service
threatengine.sh  ·  Open-source threat intelligence platform  ·  100+ authoritative sources  ·  Every fact traces to its origin