CVE-2021-3996 (GCVE-0-2021-3996)
Vulnerability from cvelistv5 – Published: 2022-08-23 00:00 – Updated: 2024-10-15 15:26
VLAI
EPSS
VEX
Summary
A logic error was found in the libmount library of util-linux in the function that allows an unprivileged user to unmount a FUSE filesystem. This flaw allows a local user on a vulnerable system to unmount other users' filesystems that are either world-writable themselves (like /tmp) or mounted in a world-writable directory. An attacker may use this flaw to cause a denial of service to applications that use the affected filesystems.
Severity
5.5 (Medium)
SSVC
Exploitation: poc
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2024-03-04 21:16 UTC
CWE
- CWE-552 - - Files or Directories Accessible to External Parties
Assigner
References
10 references
Impacted products
1 product
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| n/a | util-linux |
Affected:
Fixed in util-linux v2.37.3
|
{
"containers": {
"adp": [
{
"providerMetadata": {
"dateUpdated": "2024-08-03T17:16:02.913Z",
"orgId": "af854a3a-2127-422b-91ae-364da2661108",
"shortName": "CVE"
},
"references": [
{
"tags": [
"x_transferred"
],
"url": "https://mirrors.edge.kernel.org/pub/linux/utils/util-linux/v2.37/v2.37.3-ReleaseNotes"
},
{
"tags": [
"x_transferred"
],
"url": "https://github.com/util-linux/util-linux/commit/166e87368ae88bf31112a30e078cceae637f4cdb"
},
{
"tags": [
"x_transferred"
],
"url": "https://www.openwall.com/lists/oss-security/2022/01/24/2"
},
{
"tags": [
"x_transferred"
],
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2024628"
},
{
"tags": [
"x_transferred"
],
"url": "https://access.redhat.com/security/cve/CVE-2021-3996"
},
{
"name": "[oss-security] 20221130 Race condition in snap-confine\u0027s must_mkdir_and_open_with_perms() (CVE-2022-3328)",
"tags": [
"mailing-list",
"x_transferred"
],
"url": "http://www.openwall.com/lists/oss-security/2022/11/30/2"
},
{
"name": "20221208 Race condition in snap-confine\u0027s must_mkdir_and_open_with_perms() (CVE-2022-3328)",
"tags": [
"mailing-list",
"x_transferred"
],
"url": "http://seclists.org/fulldisclosure/2022/Dec/4"
},
{
"tags": [
"x_transferred"
],
"url": "http://packetstormsecurity.com/files/170176/snap-confine-must_mkdir_and_open_with_perms-Race-Condition.html"
},
{
"tags": [
"x_transferred"
],
"url": "https://security.netapp.com/advisory/ntap-20221209-0002/"
},
{
"name": "GLSA-202401-08",
"tags": [
"vendor-advisory",
"x_transferred"
],
"url": "https://security.gentoo.org/glsa/202401-08"
}
],
"title": "CVE Program Container"
},
{
"metrics": [
{
"cvssV3_1": {
"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"
}
},
{
"other": {
"content": {
"id": "CVE-2021-3996",
"options": [
{
"Exploitation": "poc"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2024-03-04T21:16:28.797475Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2024-10-15T15:26:56.079Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"product": "util-linux",
"vendor": "n/a",
"versions": [
{
"status": "affected",
"version": "Fixed in util-linux v2.37.3"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "A logic error was found in the libmount library of util-linux in the function that allows an unprivileged user to unmount a FUSE filesystem. This flaw allows a local user on a vulnerable system to unmount other users\u0027 filesystems that are either world-writable themselves (like /tmp) or mounted in a world-writable directory. An attacker may use this flaw to cause a denial of service to applications that use the affected filesystems."
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-552",
"description": "CWE-552 - Files or Directories Accessible to External Parties",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2024-01-07T09:06:22.825Z",
"orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
"shortName": "redhat"
},
"references": [
{
"url": "https://mirrors.edge.kernel.org/pub/linux/utils/util-linux/v2.37/v2.37.3-ReleaseNotes"
},
{
"url": "https://github.com/util-linux/util-linux/commit/166e87368ae88bf31112a30e078cceae637f4cdb"
},
{
"url": "https://www.openwall.com/lists/oss-security/2022/01/24/2"
},
{
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2024628"
},
{
"url": "https://access.redhat.com/security/cve/CVE-2021-3996"
},
{
"name": "[oss-security] 20221130 Race condition in snap-confine\u0027s must_mkdir_and_open_with_perms() (CVE-2022-3328)",
"tags": [
"mailing-list"
],
"url": "http://www.openwall.com/lists/oss-security/2022/11/30/2"
},
{
"name": "20221208 Race condition in snap-confine\u0027s must_mkdir_and_open_with_perms() (CVE-2022-3328)",
"tags": [
"mailing-list"
],
"url": "http://seclists.org/fulldisclosure/2022/Dec/4"
},
{
"url": "http://packetstormsecurity.com/files/170176/snap-confine-must_mkdir_and_open_with_perms-Race-Condition.html"
},
{
"url": "https://security.netapp.com/advisory/ntap-20221209-0002/"
},
{
"name": "GLSA-202401-08",
"tags": [
"vendor-advisory"
],
"url": "https://security.gentoo.org/glsa/202401-08"
}
]
}
},
"cveMetadata": {
"assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
"assignerShortName": "redhat",
"cveId": "CVE-2021-3996",
"datePublished": "2022-08-23T00:00:00.000Z",
"dateReserved": "2021-11-22T00:00:00.000Z",
"dateUpdated": "2024-10-15T15:26:56.079Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2021-3996",
"date": "2026-09-16",
"epss": "0.00634",
"percentile": "0.48703"
},
"fkie_nvd": {
"configurations": "[{\"nodes\": [{\"operator\": \"OR\", \"negate\": false, \"cpeMatch\": [{\"vulnerable\": true, \"criteria\": \"cpe:2.3:a:kernel:util-linux:*:*:*:*:*:*:*:*\", \"versionStartIncluding\": \"2.34\", \"versionEndExcluding\": \"2.37.3\", \"matchCriteriaId\": \"755D0AAC-24D9-4B39-BCC2-06AC9FF889E2\"}]}]}, {\"nodes\": [{\"operator\": \"OR\", \"negate\": false, \"cpeMatch\": [{\"vulnerable\": true, \"criteria\": \"cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*\", \"matchCriteriaId\": \"80E516C0-98A4-4ADE-B69F-66A772E2BAAA\"}]}]}]",
"descriptions": "[{\"lang\": \"en\", \"value\": \"A logic error was found in the libmount library of util-linux in the function that allows an unprivileged user to unmount a FUSE filesystem. This flaw allows a local user on a vulnerable system to unmount other users\u0027 filesystems that are either world-writable themselves (like /tmp) or mounted in a world-writable directory. An attacker may use this flaw to cause a denial of service to applications that use the affected filesystems.\"}, {\"lang\": \"es\", \"value\": \"Se ha encontrado un error l\\u00f3gico en la biblioteca libmount de util-linux en la funci\\u00f3n que permite a un usuario no privilegiado desmontar un sistema de archivos FUSE. Este fallo permite a un usuario local en un sistema vulnerable desmontar los sistemas de archivos de otros usuarios que son de escritura mundial (como /tmp) o que est\\u00e1n montados en un directorio de escritura mundial. Un atacante puede usar este fallo para causar una denegaci\\u00f3n de servicio a las aplicaciones que usan los sistemas de archivos afectados.\"}]",
"id": "CVE-2021-3996",
"lastModified": "2024-11-21T06:23:20.377",
"metrics": "{\"cvssMetricV31\": [{\"source\": \"nvd@nist.gov\", \"type\": \"Primary\", \"cvssData\": {\"version\": \"3.1\", \"vectorString\": \"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H\", \"baseScore\": 5.5, \"baseSeverity\": \"MEDIUM\", \"attackVector\": \"LOCAL\", \"attackComplexity\": \"LOW\", \"privilegesRequired\": \"LOW\", \"userInteraction\": \"NONE\", \"scope\": \"UNCHANGED\", \"confidentialityImpact\": \"NONE\", \"integrityImpact\": \"NONE\", \"availabilityImpact\": \"HIGH\"}, \"exploitabilityScore\": 1.8, \"impactScore\": 3.6}, {\"source\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"type\": \"Secondary\", \"cvssData\": {\"version\": \"3.1\", \"vectorString\": \"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H\", \"baseScore\": 5.5, \"baseSeverity\": \"MEDIUM\", \"attackVector\": \"LOCAL\", \"attackComplexity\": \"LOW\", \"privilegesRequired\": \"LOW\", \"userInteraction\": \"NONE\", \"scope\": \"UNCHANGED\", \"confidentialityImpact\": \"NONE\", \"integrityImpact\": \"NONE\", \"availabilityImpact\": \"HIGH\"}, \"exploitabilityScore\": 1.8, \"impactScore\": 3.6}]}",
"published": "2022-08-23T20:15:08.560",
"references": "[{\"url\": \"http://packetstormsecurity.com/files/170176/snap-confine-must_mkdir_and_open_with_perms-Race-Condition.html\", \"source\": \"secalert@redhat.com\", \"tags\": [\"Third Party Advisory\"]}, {\"url\": \"http://seclists.org/fulldisclosure/2022/Dec/4\", \"source\": \"secalert@redhat.com\", \"tags\": [\"Mailing List\", \"Third Party Advisory\"]}, {\"url\": \"http://www.openwall.com/lists/oss-security/2022/11/30/2\", \"source\": \"secalert@redhat.com\", \"tags\": [\"Mailing List\", \"Third Party Advisory\"]}, {\"url\": \"https://access.redhat.com/security/cve/CVE-2021-3996\", \"source\": \"secalert@redhat.com\", \"tags\": [\"Issue Tracking\", \"Third Party Advisory\"]}, {\"url\": \"https://bugzilla.redhat.com/show_bug.cgi?id=2024628\", \"source\": \"secalert@redhat.com\", \"tags\": [\"Issue Tracking\", \"Patch\", \"Third Party Advisory\"]}, {\"url\": \"https://github.com/util-linux/util-linux/commit/166e87368ae88bf31112a30e078cceae637f4cdb\", \"source\": \"secalert@redhat.com\", \"tags\": [\"Patch\", \"Third Party Advisory\"]}, {\"url\": \"https://mirrors.edge.kernel.org/pub/linux/utils/util-linux/v2.37/v2.37.3-ReleaseNotes\", \"source\": \"secalert@redhat.com\", \"tags\": [\"Release Notes\", \"Vendor Advisory\"]}, {\"url\": \"https://security.gentoo.org/glsa/202401-08\", \"source\": \"secalert@redhat.com\"}, {\"url\": \"https://security.netapp.com/advisory/ntap-20221209-0002/\", \"source\": \"secalert@redhat.com\", \"tags\": [\"Broken Link\", \"Third Party Advisory\"]}, {\"url\": \"https://www.openwall.com/lists/oss-security/2022/01/24/2\", \"source\": \"secalert@redhat.com\", \"tags\": [\"Exploit\", \"Mailing List\", \"Patch\", \"Third Party Advisory\"]}, {\"url\": \"http://packetstormsecurity.com/files/170176/snap-confine-must_mkdir_and_open_with_perms-Race-Condition.html\", \"source\": \"af854a3a-2127-422b-91ae-364da2661108\", \"tags\": [\"Third Party Advisory\"]}, {\"url\": \"http://seclists.org/fulldisclosure/2022/Dec/4\", \"source\": \"af854a3a-2127-422b-91ae-364da2661108\", \"tags\": [\"Mailing List\", \"Third Party Advisory\"]}, {\"url\": \"http://www.openwall.com/lists/oss-security/2022/11/30/2\", \"source\": \"af854a3a-2127-422b-91ae-364da2661108\", \"tags\": [\"Mailing List\", \"Third Party Advisory\"]}, {\"url\": \"https://access.redhat.com/security/cve/CVE-2021-3996\", \"source\": \"af854a3a-2127-422b-91ae-364da2661108\", \"tags\": [\"Issue Tracking\", \"Third Party Advisory\"]}, {\"url\": \"https://bugzilla.redhat.com/show_bug.cgi?id=2024628\", \"source\": \"af854a3a-2127-422b-91ae-364da2661108\", \"tags\": [\"Issue Tracking\", \"Patch\", \"Third Party Advisory\"]}, {\"url\": \"https://github.com/util-linux/util-linux/commit/166e87368ae88bf31112a30e078cceae637f4cdb\", \"source\": \"af854a3a-2127-422b-91ae-364da2661108\", \"tags\": [\"Patch\", \"Third Party Advisory\"]}, {\"url\": \"https://mirrors.edge.kernel.org/pub/linux/utils/util-linux/v2.37/v2.37.3-ReleaseNotes\", \"source\": \"af854a3a-2127-422b-91ae-364da2661108\", \"tags\": [\"Release Notes\", \"Vendor Advisory\"]}, {\"url\": \"https://security.gentoo.org/glsa/202401-08\", \"source\": \"af854a3a-2127-422b-91ae-364da2661108\"}, {\"url\": \"https://security.netapp.com/advisory/ntap-20221209-0002/\", \"source\": \"af854a3a-2127-422b-91ae-364da2661108\", \"tags\": [\"Broken Link\", \"Third Party Advisory\"]}, {\"url\": \"https://www.openwall.com/lists/oss-security/2022/01/24/2\", \"source\": \"af854a3a-2127-422b-91ae-364da2661108\", \"tags\": [\"Exploit\", \"Mailing List\", \"Patch\", \"Third Party Advisory\"]}]",
"sourceIdentifier": "secalert@redhat.com",
"vulnStatus": "Modified",
"weaknesses": "[{\"source\": \"secalert@redhat.com\", \"type\": \"Primary\", \"description\": [{\"lang\": \"en\", \"value\": \"CWE-552\"}]}, {\"source\": \"nvd@nist.gov\", \"type\": \"Secondary\", \"description\": [{\"lang\": \"en\", \"value\": \"CWE-552\"}]}]"
},
"microsoft_vex": {
"current_release_date": "2025-10-01T23:11:12.000Z",
"cve": "CVE-2021-3996",
"id": "msrc_CVE-2021-3996",
"initial_release_date": "2022-08-02T00:00:00.000Z",
"product_status:fixed": "1",
"product_status:known_affected": "1",
"source": "Microsoft CSAF VEX",
"status": "final",
"title": "A logic error was found in the libmount library of util-linux in the function that allows an unprivileged user to unmount a FUSE filesystem. This flaw allows a local user on a vulnerable system to unmount other users\u0027 filesystems that are either world-writable themselves (like /tmp) or mounted in a world-writable directory. An attacker may use this flaw to cause a denial of service to applications that use the affected filesystems.",
"url": "https://msrc.microsoft.com/csaf/vex/2022/msrc_cve-2021-3996.json",
"version": "1"
},
"nvd": "{\"cve\":{\"id\":\"CVE-2021-3996\",\"sourceIdentifier\":\"secalert@redhat.com\",\"published\":\"2022-08-23T20:15:08.560\",\"lastModified\":\"2026-06-17T04:06:21.753\",\"vulnStatus\":\"Modified\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"A logic error was found in the libmount library of util-linux in the function that allows an unprivileged user to unmount a FUSE filesystem. This flaw allows a local user on a vulnerable system to unmount other users\u0027 filesystems that are either world-writable themselves (like /tmp) or mounted in a world-writable directory. An attacker may use this flaw to cause a denial of service to applications that use the affected filesystems.\"},{\"lang\":\"es\",\"value\":\"Se ha encontrado un error l\u00f3gico en la biblioteca libmount de util-linux en la funci\u00f3n que permite a un usuario no privilegiado desmontar un sistema de archivos FUSE. Este fallo permite a un usuario local en un sistema vulnerable desmontar los sistemas de archivos de otros usuarios que son de escritura mundial (como /tmp) o que est\u00e1n montados en un directorio de escritura mundial. Un atacante puede usar este fallo para causar una denegaci\u00f3n de servicio a las aplicaciones que usan los sistemas de archivos afectados.\"}],\"affected\":[{\"source\":\"secalert@redhat.com\",\"affectedData\":[{\"vendor\":\"n/a\",\"product\":\"util-linux\",\"versions\":[{\"version\":\"Fixed in util-linux v2.37.3\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H\",\"baseScore\":5.5,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.8,\"impactScore\":3.6},{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H\",\"baseScore\":5.5,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.8,\"impactScore\":3.6}],\"ssvcV203\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"ssvcData\":{\"timestamp\":\"2024-03-04T21:16:28.797475Z\",\"id\":\"CVE-2021-3996\",\"options\":[{\"exploitation\":\"poc\"},{\"automatable\":\"no\"},{\"technicalImpact\":\"partial\"}],\"role\":\"CISA Coordinator\",\"version\":\"2.0.3\"}}]},\"weaknesses\":[{\"source\":\"secalert@redhat.com\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-552\"}]},{\"source\":\"nvd@nist.gov\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-552\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:kernel:util-linux:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"2.34\",\"versionEndExcluding\":\"2.37.3\",\"matchCriteriaId\":\"755D0AAC-24D9-4B39-BCC2-06AC9FF889E2\"}]}]},{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*\",\"matchCriteriaId\":\"80E516C0-98A4-4ADE-B69F-66A772E2BAAA\"}]}]}],\"references\":[{\"url\":\"http://packetstormsecurity.com/files/170176/snap-confine-must_mkdir_and_open_with_perms-Race-Condition.html\",\"source\":\"secalert@redhat.com\",\"tags\":[\"Third Party Advisory\"]},{\"url\":\"http://seclists.org/fulldisclosure/2022/Dec/4\",\"source\":\"secalert@redhat.com\",\"tags\":[\"Mailing List\",\"Third Party Advisory\"]},{\"url\":\"http://www.openwall.com/lists/oss-security/2022/11/30/2\",\"source\":\"secalert@redhat.com\",\"tags\":[\"Mailing List\",\"Third Party Advisory\"]},{\"url\":\"https://access.redhat.com/security/cve/CVE-2021-3996\",\"source\":\"secalert@redhat.com\",\"tags\":[\"Issue Tracking\",\"Third Party Advisory\"]},{\"url\":\"https://bugzilla.redhat.com/show_bug.cgi?id=2024628\",\"source\":\"secalert@redhat.com\",\"tags\":[\"Issue Tracking\",\"Patch\",\"Third Party Advisory\"]},{\"url\":\"https://github.com/util-linux/util-linux/commit/166e87368ae88bf31112a30e078cceae637f4cdb\",\"source\":\"secalert@redhat.com\",\"tags\":[\"Patch\",\"Third Party Advisory\"]},{\"url\":\"https://mirrors.edge.kernel.org/pub/linux/utils/util-linux/v2.37/v2.37.3-ReleaseNotes\",\"source\":\"secalert@redhat.com\",\"tags\":[\"Release Notes\",\"Vendor Advisory\"]},{\"url\":\"https://security.gentoo.org/glsa/202401-08\",\"source\":\"secalert@redhat.com\"},{\"url\":\"https://security.netapp.com/advisory/ntap-20221209-0002/\",\"source\":\"secalert@redhat.com\",\"tags\":[\"Broken Link\",\"Third Party Advisory\"]},{\"url\":\"https://www.openwall.com/lists/oss-security/2022/01/24/2\",\"source\":\"secalert@redhat.com\",\"tags\":[\"Exploit\",\"Mailing List\",\"Patch\",\"Third Party Advisory\"]},{\"url\":\"http://packetstormsecurity.com/files/170176/snap-confine-must_mkdir_and_open_with_perms-Race-Condition.html\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Third Party Advisory\"]},{\"url\":\"http://seclists.org/fulldisclosure/2022/Dec/4\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Mailing List\",\"Third Party Advisory\"]},{\"url\":\"http://www.openwall.com/lists/oss-security/2022/11/30/2\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Mailing List\",\"Third Party Advisory\"]},{\"url\":\"https://access.redhat.com/security/cve/CVE-2021-3996\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Issue Tracking\",\"Third Party Advisory\"]},{\"url\":\"https://bugzilla.redhat.com/show_bug.cgi?id=2024628\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Issue Tracking\",\"Patch\",\"Third Party Advisory\"]},{\"url\":\"https://github.com/util-linux/util-linux/commit/166e87368ae88bf31112a30e078cceae637f4cdb\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Patch\",\"Third Party Advisory\"]},{\"url\":\"https://mirrors.edge.kernel.org/pub/linux/utils/util-linux/v2.37/v2.37.3-ReleaseNotes\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Release Notes\",\"Vendor Advisory\"]},{\"url\":\"https://security.gentoo.org/glsa/202401-08\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\"},{\"url\":\"https://security.netapp.com/advisory/ntap-20221209-0002/\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Broken Link\",\"Third Party Advisory\"]},{\"url\":\"https://www.openwall.com/lists/oss-security/2022/01/24/2\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Exploit\",\"Mailing List\",\"Patch\",\"Third Party Advisory\"]}]}}",
"redhat_vex": {
"aggregate_severity": "Moderate",
"current_release_date": "2025-11-21T14:31:53+00:00",
"cve": "CVE-2021-3996",
"id": "CVE-2021-3996",
"initial_release_date": "2021-01-01T00:00:00+00:00",
"product_status:known_not_affected": "45",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "util-linux: Unauthorized unmount of filesystems in libmount",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2021/cve-2021-3996.json",
"version": "3"
},
"suse_vex": {
"aggregate_severity": "moderate",
"current_release_date": "2026-08-31T02:10:10Z",
"cve": "CVE-2021-3996",
"id": "CVE-2021-3996",
"initial_release_date": "2023-02-15T03:48:16Z",
"product_status:known_affected": "347",
"product_status:known_not_affected": "787",
"product_status:recommended": "847",
"source": "SUSE CSAF VEX",
"status": "interim",
"title": "SUSE CVE CVE-2021-3996",
"url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2021-3996.json",
"version": "46"
},
"vulnrichment": {
"containers": "{\"adp\": [{\"title\": \"CVE Program Container\", \"references\": [{\"url\": \"https://mirrors.edge.kernel.org/pub/linux/utils/util-linux/v2.37/v2.37.3-ReleaseNotes\", \"tags\": [\"x_transferred\"]}, {\"url\": \"https://github.com/util-linux/util-linux/commit/166e87368ae88bf31112a30e078cceae637f4cdb\", \"tags\": [\"x_transferred\"]}, {\"url\": \"https://www.openwall.com/lists/oss-security/2022/01/24/2\", \"tags\": [\"x_transferred\"]}, {\"url\": \"https://bugzilla.redhat.com/show_bug.cgi?id=2024628\", \"tags\": [\"x_transferred\"]}, {\"url\": \"https://access.redhat.com/security/cve/CVE-2021-3996\", \"tags\": [\"x_transferred\"]}, {\"url\": \"http://www.openwall.com/lists/oss-security/2022/11/30/2\", \"name\": \"[oss-security] 20221130 Race condition in snap-confine\u0027s must_mkdir_and_open_with_perms() (CVE-2022-3328)\", \"tags\": [\"mailing-list\", \"x_transferred\"]}, {\"url\": \"http://seclists.org/fulldisclosure/2022/Dec/4\", \"name\": \"20221208 Race condition in snap-confine\u0027s must_mkdir_and_open_with_perms() (CVE-2022-3328)\", \"tags\": [\"mailing-list\", \"x_transferred\"]}, {\"url\": \"http://packetstormsecurity.com/files/170176/snap-confine-must_mkdir_and_open_with_perms-Race-Condition.html\", \"tags\": [\"x_transferred\"]}, {\"url\": \"https://security.netapp.com/advisory/ntap-20221209-0002/\", \"tags\": [\"x_transferred\"]}, {\"url\": \"https://security.gentoo.org/glsa/202401-08\", \"name\": \"GLSA-202401-08\", \"tags\": [\"vendor-advisory\", \"x_transferred\"]}], \"providerMetadata\": {\"orgId\": \"af854a3a-2127-422b-91ae-364da2661108\", \"shortName\": \"CVE\", \"dateUpdated\": \"2024-08-03T17:16:02.913Z\"}}, {\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"cvssV3_1\": {\"scope\": \"UNCHANGED\", \"version\": \"3.1\", \"baseScore\": 5.5, \"attackVector\": \"LOCAL\", \"baseSeverity\": \"MEDIUM\", \"vectorString\": \"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H\", \"integrityImpact\": \"NONE\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"HIGH\", \"privilegesRequired\": \"LOW\", \"confidentialityImpact\": \"NONE\"}}, {\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2021-3996\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"poc\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2024-03-04T21:16:28.797475Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2024-10-15T15:26:41.487Z\"}}], \"cna\": {\"affected\": [{\"vendor\": \"n/a\", \"product\": \"util-linux\", \"versions\": [{\"status\": \"affected\", \"version\": \"Fixed in util-linux v2.37.3\"}]}], \"references\": [{\"url\": \"https://mirrors.edge.kernel.org/pub/linux/utils/util-linux/v2.37/v2.37.3-ReleaseNotes\"}, {\"url\": \"https://github.com/util-linux/util-linux/commit/166e87368ae88bf31112a30e078cceae637f4cdb\"}, {\"url\": \"https://www.openwall.com/lists/oss-security/2022/01/24/2\"}, {\"url\": \"https://bugzilla.redhat.com/show_bug.cgi?id=2024628\"}, {\"url\": \"https://access.redhat.com/security/cve/CVE-2021-3996\"}, {\"url\": \"http://www.openwall.com/lists/oss-security/2022/11/30/2\", \"name\": \"[oss-security] 20221130 Race condition in snap-confine\u0027s must_mkdir_and_open_with_perms() (CVE-2022-3328)\", \"tags\": [\"mailing-list\"]}, {\"url\": \"http://seclists.org/fulldisclosure/2022/Dec/4\", \"name\": \"20221208 Race condition in snap-confine\u0027s must_mkdir_and_open_with_perms() (CVE-2022-3328)\", \"tags\": [\"mailing-list\"]}, {\"url\": \"http://packetstormsecurity.com/files/170176/snap-confine-must_mkdir_and_open_with_perms-Race-Condition.html\"}, {\"url\": \"https://security.netapp.com/advisory/ntap-20221209-0002/\"}, {\"url\": \"https://security.gentoo.org/glsa/202401-08\", \"name\": \"GLSA-202401-08\", \"tags\": [\"vendor-advisory\"]}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"A logic error was found in the libmount library of util-linux in the function that allows an unprivileged user to unmount a FUSE filesystem. This flaw allows a local user on a vulnerable system to unmount other users\u0027 filesystems that are either world-writable themselves (like /tmp) or mounted in a world-writable directory. An attacker may use this flaw to cause a denial of service to applications that use the affected filesystems.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-552\", \"description\": \"CWE-552 - Files or Directories Accessible to External Parties\"}]}], \"providerMetadata\": {\"orgId\": \"53f830b8-0a3f-465b-8143-3b8a9948e749\", \"shortName\": \"redhat\", \"dateUpdated\": \"2024-01-07T09:06:22.825Z\"}}}",
"cveMetadata": "{\"cveId\": \"CVE-2021-3996\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2024-10-15T15:26:56.079Z\", \"dateReserved\": \"2021-11-22T00:00:00.000Z\", \"assignerOrgId\": \"53f830b8-0a3f-465b-8143-3b8a9948e749\", \"datePublished\": \"2022-08-23T00:00:00.000Z\", \"assignerShortName\": \"redhat\"}",
"dataType": "CVE_RECORD",
"dataVersion": "5.1"
}
}
}
Loading…
Loading…
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.
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.
Loading…