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Back to active CVEs
Unknown severity · Source severity not reportedCVE-2021-3997

CVE Program ContainerCVE-2021-3997

Answer in brief

CVE-2021-3997 records a Unknown severity vulnerability in CVE Program Container. The current sources do not mark it as known exploited. The current feed maps Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic), Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (generic), Siemens/SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (generic), n/a/systemd (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Aug 23, 2022Updated Oct 14, 2026Source checked Oct 14, 2026First seen by HOL Oct 14, 2026Material review Oct 14, 2026
Upstream Advisory

Key facts

Risk
Unknown severitySource severity not reported
Exploitation
Not marked as known exploited
Affected software
4 mapped packages or products
Fix availability
Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic), Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (generic), Siemens/SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (generic), n/a/systemd (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
PackageAffected rangeFixed version
Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFPgeneric>=V3.1.0 <V3.1.5V3.1.5
Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPgeneric>=V3.1.0 <V3.1.5V3.1.5
Siemens/SIPLUS S7-1500 CPU 1518-4 PN/DP MFPgeneric>=V3.1.0 <V3.1.5V3.1.5
n/a/systemdgenericFixed in v251-rc1Not reported

Recommended response

  1. 1Check inventory. Check lockfiles and deployed manifests for Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP, Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP, Siemens/SIPLUS S7-1500 CPU 1518-4 PN/DP MFP.
  2. 2Review the reported fix. Update Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP to V3.1.5; Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP to V3.1.5; Siemens/SIPLUS S7-1500 CPU 1518-4 PN/DP MFP to V3.1.5 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

  1. Published upstream

    Aug 23, 2022

    Evidence: source:cvelist:source_dates:source-dates:record

  2. Source modified

    Oct 14, 2026

    Evidence: source:cvelist:source_dates:source-dates:record

  3. First seen by HOL

    Oct 14, 2026

Sources and claim methodology

  • Source referenceaccess.redhat.com
  • Source referencebugzilla.redhat.com
  • Source referencecert-portal.siemens.com
  • GitHub security advisorygithub.com
  • Source referencesecurity.gentoo.org
  • Source referenceopenwall.com
Upstream source 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.

Quoted source text, attributed separately from HOL analysis.

Related CVEs

  • PeproDev Branches Map <= 3.0.1 - Authenticated (Contributor+) Stored Cross-Site ScriptingSame generic ecosystem
  • Gstreamer1-plugins-bad-free: gstreamer1-plugins-bad-free: out-of-bounds write in gst_h266_parser_parse_dci() due to off-by-one array bound checkSame generic ecosystem
  • Gstreamer1-plugins-bad-free: gstreamer1-plugins-bad-free: heap out-of-bounds write in asfmux due to incorrect utf-16 size calculation for non-bmp charactersSame generic ecosystem
  • WPCode 2.0.0 - 2.3.9 - Unauthenticated Snippet Suppression via Safe Mode BypassSame generic ecosystem
  • Stack overwrite from specially formatted base64 RDATA fieldSame generic ecosystem
  • Stack overwrite from a specially crafted and formatted SVCB or HTTPS RRSame generic ecosystem

Record context

Vulnerability class
Vulnerability
EPSS
Not reported
CWE IDs
CWE-674
Source
CVE List V5
Source checked
Oct 14, 2026
References
6 linked sources
Open source record