How severe is CVE-2021-3997?

CVE-2021-3997 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-3997 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (72nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-3997?

CVE-2021-3997 primarily affects Redhat Enterprise Linux. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-3997?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-3997 published?

CVE-2021-3997 was published on 2022-08-23 and last updated on 2026-06-17.

CVE-2021-3997

CVE-2021-3997 is a medium-severity vulnerability in Redhat Enterprise Linux with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-674.

Key facts

Severity: Medium (CVSS 3.x base score 5.5)
EPSS exploit prediction: 2% (72nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-674
Affected product: Redhat Enterprise Linux
Published: 2022-08-23
Last modified: 2026-06-17

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.

Frequently asked questions

What is 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 when too many nested directories are created in /tmp.
How severe is CVE-2021-3997?: CVE-2021-3997 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-3997 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (72nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-3997?: CVE-2021-3997 primarily affects Redhat Enterprise Linux. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-3997?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-3997 published?: CVE-2021-3997 was published on 2022-08-23 and last updated on 2026-06-17.

References

Affected products (6)

cpe:2.3:a:systemd_project:systemd:*:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*

More vulnerabilities in Redhat Enterprise Linux

CVE-2015-0240 — Critical (CVSS 10.0): The Netlogon server implementation in smbd in Samba 3.5.x and 3.6.x before 3.6.25, 4.0.x before 4.0.25, 4.1.x before…
CVE-2015-0408 — Critical (CVSS 10.0): Unspecified vulnerability in Oracle Java SE 5.0u75, 6u85, 7u72, and 8u25 allows remote attackers to affect…
CVE-2014-6601 — Critical (CVSS 10.0): Unspecified vulnerability in Oracle Java SE 6u85, 7u72, and 8u25 allows remote attackers to affect confidentiality,…
CVE-2009-0846 — Critical (CVSS 10.0): The asn1_decode_generaltime function in lib/krb5/asn.1/asn1_decode.c in the ASN.1 GeneralizedTime decoder in MIT…
CVE-2007-1007 — Critical (CVSS 10.0): Format string vulnerability in GnomeMeeting 1.0.2 and earlier allows remote attackers to cause a denial of service…
CVE-2006-6235 — Critical (CVSS 10.0): A "stack overwrite" vulnerability in GnuPG (gpg) 1.x before 1.4.6, 2.x before 2.0.2, and 1.9.0 through 1.9.95 allows…

All CVEs affecting Redhat Enterprise Linux →

Other CWE-674 (Uncontrolled Recursion) vulnerabilities

CVE-2026-43185 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix signededness bug in…
CVE-2023-51803 — Critical (CVSS 9.8): LinuxServer.io Heimdall before 2.5.7 does not prevent use of icons that have non-image data such as the "<?php ?>"…
CVE-2021-41752 — Critical (CVSS 9.8): Stack overflow vulnerability in Jerryscript before commit e1ce7dd7271288be8c0c8136eea9107df73a8ce2 on Oct 20, 2021 due…
CVE-2018-1000618 — Critical (CVSS 9.8): EOSIO/eos eos version after commit f1545dd0ae2b77580c2236fdb70ae7138d2c7168 contains a stack overflow vulnerability in…
CVE-2025-10728 — Critical (CVSS 9.4): When the module renders a Svg file that contains a <pattern> element, it might end up rendering it recursively leading…
CVE-2026-40324 — Critical (CVSS 9.1): Hot Chocolate is an open-source GraphQL server. Prior to versions 12.22.7, 13.9.16, 14.3.1, and 15.1.14, Hot…

Browse all CWE-674 (Uncontrolled Recursion) vulnerabilities →