Medium severity · published Aug 23, 2022
CVE-2021-3997
A flaw was found in systemd
5.5
CVSS
1.7%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)1.7% · higher than 78% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
SY
systemd ·
Fixed in v251-rc1 · source: vendor, NVD
EL
Enterprise Linux · Redhat
7.0; 8.0; 9.0 · source: NVD
FE
Fedora · Fedoraproject
34; 35 · source: NVD
SS
SIMATIC S7-1500 CPU 1518-4 PN/DP MFP · Siemens
V3.1.0 before V3.1.5; V3.1.0 before V3.1.5 · source: CISA
SS
SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP · Siemens
V3.1.0 before V3.1.5; V3.1.0 before V3.1.5 · source: CISA
SS
SIPLUS S7-1500 CPU 1518-4 PN/DP MFP · Siemens
V3.1.0 before V3.1.5 · source: CISA
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-3997
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-3997
Issue Tracking
https://access.redhat.com/security/cve/CVE-2021-3997
Issue Tracking
https://bugzilla.redhat.com/show_bug.cgi?id=2024639
Patch
https://github.com/systemd/systemd/commit/5b1cf7a9be37e20133c0208005274ce4a5b5c6a1
security.gentoo.org
https://security.gentoo.org/glsa/202305-15
Exploit
https://www.openwall.com/lists/oss-security/2022/01/10/2
cert-portal.siemens.com
https://cert-portal.siemens.com/productcert/html/ssa-398330.html
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