CVE-2021-3997 (GCVE-0-2021-3997)
Vulnerability from cvelistv5 – Published: 2022-08-23 00:00 – Updated: 2026-10-14 09:49
VLAI
EPSS
VEX
Summary
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.
Severity
5.5 (Medium)
CWE
- CWE-674 - - Uncontrolled Recursion
Assigner
References
6 references
Impacted products
4 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| n/a | systemd |
Affected:
Fixed in v251-rc1
|
||
| Siemens | SIMATIC S7-1500 CPU 1518-4 PN/DP MFP |
Affected:
V3.1.0 , < V3.1.5
(custom)
|
guessed | |
| Siemens | SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP |
Affected:
V3.1.0 , < V3.1.5
(custom)
|
guessed | |
| Siemens | SIPLUS S7-1500 CPU 1518-4 PN/DP MFP |
Affected:
V3.1.0 , < V3.1.5
(custom)
|
guessed |
{
"containers": {
"adp": [
{
"providerMetadata": {
"dateUpdated": "2024-08-03T17:16:02.914Z",
"orgId": "af854a3a-2127-422b-91ae-364da2661108",
"shortName": "CVE"
},
"references": [
{
"tags": [
"x_transferred"
],
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2024639"
},
{
"tags": [
"x_transferred"
],
"url": "https://www.openwall.com/lists/oss-security/2022/01/10/2"
},
{
"tags": [
"x_transferred"
],
"url": "https://github.com/systemd/systemd/commit/5b1cf7a9be37e20133c0208005274ce4a5b5c6a1"
},
{
"tags": [
"x_transferred"
],
"url": "https://access.redhat.com/security/cve/CVE-2021-3997"
},
{
"name": "GLSA-202305-15",
"tags": [
"vendor-advisory",
"x_transferred"
],
"url": "https://security.gentoo.org/glsa/202305-15"
}
],
"title": "CVE Program Container"
},
{
"affected": [
{
"defaultStatus": "unknown",
"product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP",
"vendor": "Siemens",
"versions": [
{
"lessThan": "V3.1.5",
"status": "affected",
"version": "V3.1.0",
"versionType": "custom"
}
]
},
{
"defaultStatus": "unknown",
"product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP",
"vendor": "Siemens",
"versions": [
{
"lessThan": "V3.1.5",
"status": "affected",
"version": "V3.1.0",
"versionType": "custom"
}
]
},
{
"defaultStatus": "unknown",
"product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP",
"vendor": "Siemens",
"versions": [
{
"lessThan": "V3.1.5",
"status": "affected",
"version": "V3.1.0",
"versionType": "custom"
}
]
},
{
"defaultStatus": "unknown",
"product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP",
"vendor": "Siemens",
"versions": [
{
"lessThan": "V3.1.5",
"status": "affected",
"version": "V3.1.0",
"versionType": "custom"
}
]
},
{
"defaultStatus": "unknown",
"product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP",
"vendor": "Siemens",
"versions": [
{
"lessThan": "V3.1.5",
"status": "affected",
"version": "V3.1.0",
"versionType": "custom"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-10-14T09:49:55.103Z",
"orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e",
"shortName": "siemens-SADP"
},
"references": [
{
"url": "https://cert-portal.siemens.com/productcert/html/ssa-398330.html"
}
],
"x_adpType": "supplier"
}
],
"cna": {
"affected": [
{
"product": "systemd",
"vendor": "n/a",
"versions": [
{
"status": "affected",
"version": "Fixed in v251-rc1"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "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."
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-674",
"description": "CWE-674 - Uncontrolled Recursion",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2023-05-03T00:00:00.000Z",
"orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
"shortName": "redhat"
},
"references": [
{
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2024639"
},
{
"url": "https://www.openwall.com/lists/oss-security/2022/01/10/2"
},
{
"url": "https://github.com/systemd/systemd/commit/5b1cf7a9be37e20133c0208005274ce4a5b5c6a1"
},
{
"url": "https://access.redhat.com/security/cve/CVE-2021-3997"
},
{
"name": "GLSA-202305-15",
"tags": [
"vendor-advisory"
],
"url": "https://security.gentoo.org/glsa/202305-15"
}
]
}
},
"cveMetadata": {
"assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
"assignerShortName": "redhat",
"cveId": "CVE-2021-3997",
"datePublished": "2022-08-23T00:00:00.000Z",
"dateReserved": "2021-11-22T00:00:00.000Z",
"dateUpdated": "2026-10-14T09:49:55.103Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2021-3997",
"date": "2026-10-14",
"epss": "0.01701",
"percentile": "0.76759"
},
"microsoft_vex": {
"current_release_date": "2022-08-27T00:00:00.000Z",
"cve": "CVE-2021-3997",
"id": "msrc_CVE-2021-3997",
"initial_release_date": "2022-08-02T00:00:00.000Z",
"product_status:fixed": "2",
"product_status:known_affected": "2",
"source": "Microsoft CSAF VEX",
"status": "final",
"title": "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.",
"url": "https://msrc.microsoft.com/csaf/vex/2022/msrc_cve-2021-3997.json",
"version": "1"
},
"nvd": {
"cve": {
"affected": [
{
"affectedData": [
{
"product": "systemd",
"vendor": "n/a",
"versions": [
{
"status": "affected",
"version": "Fixed in v251-rc1"
}
]
}
],
"source": "secalert@redhat.com"
},
{
"affectedData": [
{
"defaultStatus": "unknown",
"product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP",
"vendor": "Siemens",
"versions": [
{
"lessThan": "V3.1.5",
"status": "affected",
"version": "V3.1.0",
"versionType": "custom"
}
]
},
{
"defaultStatus": "unknown",
"product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP",
"vendor": "Siemens",
"versions": [
{
"lessThan": "V3.1.5",
"status": "affected",
"version": "V3.1.0",
"versionType": "custom"
}
]
},
{
"defaultStatus": "unknown",
"product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP",
"vendor": "Siemens",
"versions": [
{
"lessThan": "V3.1.5",
"status": "affected",
"version": "V3.1.0",
"versionType": "custom"
}
]
},
{
"defaultStatus": "unknown",
"product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP",
"vendor": "Siemens",
"versions": [
{
"lessThan": "V3.1.5",
"status": "affected",
"version": "V3.1.0",
"versionType": "custom"
}
]
},
{
"defaultStatus": "unknown",
"product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP",
"vendor": "Siemens",
"versions": [
{
"lessThan": "V3.1.5",
"status": "affected",
"version": "V3.1.0",
"versionType": "custom"
}
]
}
],
"source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"
}
],
"configurations": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:a:systemd_project:systemd:*:*:*:*:*:*:*:*",
"matchCriteriaId": "0D5DB179-3322-4645-BF16-007AE6A8378D",
"versionEndExcluding": "250.2",
"versionStartIncluding": "240",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
},
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*",
"matchCriteriaId": "A930E247-0B43-43CB-98FF-6CE7B8189835",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*",
"matchCriteriaId": "80E516C0-98A4-4ADE-B69F-66A772E2BAAA",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
},
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*",
"matchCriteriaId": "142AD0DD-4CF3-4D74-9442-459CE3347E3A",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*",
"matchCriteriaId": "F4CFF558-3C47-480D-A2F0-BABF26042943",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*",
"matchCriteriaId": "7F6FB57C-2BC7-487C-96DD-132683AEB35D",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "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."
},
{
"lang": "es",
"value": "Se ha encontrado un fallo en systemd. Una recursi\u00f3n no controlada en systemd-tmpfiles puede conllevar a una denegaci\u00f3n de servicio en el momento del arranque cuando son creados demasiados directorios anidados en /tmp."
}
],
"id": "CVE-2021-3997",
"lastModified": "2026-10-14T10:17:49.307",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "HIGH",
"baseScore": 5.5,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"version": "3.1"
},
"exploitabilityScore": 1.8,
"impactScore": 3.6,
"source": "nvd@nist.gov",
"type": "Primary"
}
]
},
"published": "2022-08-23T20:15:08.670",
"references": [
{
"source": "secalert@redhat.com",
"tags": [
"Issue Tracking",
"Third Party Advisory"
],
"url": "https://access.redhat.com/security/cve/CVE-2021-3997"
},
{
"source": "secalert@redhat.com",
"tags": [
"Issue Tracking",
"Patch",
"Third Party Advisory"
],
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2024639"
},
{
"source": "secalert@redhat.com",
"tags": [
"Patch",
"Third Party Advisory"
],
"url": "https://github.com/systemd/systemd/commit/5b1cf7a9be37e20133c0208005274ce4a5b5c6a1"
},
{
"source": "secalert@redhat.com",
"url": "https://security.gentoo.org/glsa/202305-15"
},
{
"source": "secalert@redhat.com",
"tags": [
"Exploit",
"Mailing List",
"Third Party Advisory"
],
"url": "https://www.openwall.com/lists/oss-security/2022/01/10/2"
},
{
"source": "af854a3a-2127-422b-91ae-364da2661108",
"tags": [
"Issue Tracking",
"Third Party Advisory"
],
"url": "https://access.redhat.com/security/cve/CVE-2021-3997"
},
{
"source": "af854a3a-2127-422b-91ae-364da2661108",
"tags": [
"Issue Tracking",
"Patch",
"Third Party Advisory"
],
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2024639"
},
{
"source": "af854a3a-2127-422b-91ae-364da2661108",
"tags": [
"Patch",
"Third Party Advisory"
],
"url": "https://github.com/systemd/systemd/commit/5b1cf7a9be37e20133c0208005274ce4a5b5c6a1"
},
{
"source": "af854a3a-2127-422b-91ae-364da2661108",
"url": "https://security.gentoo.org/glsa/202305-15"
},
{
"source": "af854a3a-2127-422b-91ae-364da2661108",
"tags": [
"Exploit",
"Mailing List",
"Third Party Advisory"
],
"url": "https://www.openwall.com/lists/oss-security/2022/01/10/2"
},
{
"source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e",
"url": "https://cert-portal.siemens.com/productcert/html/ssa-398330.html"
}
],
"sourceIdentifier": "secalert@redhat.com",
"vulnStatus": "Modified",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-674"
}
],
"source": "secalert@redhat.com",
"type": "Secondary"
},
{
"description": [
{
"lang": "en",
"value": "CWE-674"
}
],
"source": "nvd@nist.gov",
"type": "Primary"
}
]
}
},
"redhat_vex": {
"aggregate_severity": "Moderate",
"current_release_date": "2026-01-21T19:21:10+00:00",
"cve": "CVE-2021-3997",
"id": "CVE-2021-3997",
"initial_release_date": "2021-01-01T00:00:00+00:00",
"product_status:known_affected": "20",
"product_status:known_not_affected": "14",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "systemd: Uncontrolled recursion in systemd-tmpfiles when removing files",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2021/cve-2021-3997.json",
"version": "3"
}
}
}
Loading…
Loading…
Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.
Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Vulnerability timeline
Sightings and recorded dates, grouped by day · UTC
Loading timeline…
Loading…
Loading…
The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Loading…
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.