{"containers": {"cna": {"affected": [{"product": "linux kernel", "vendor": "Ubuntu", "versions": [{"lessThan": "5.8.0-50.56", "status": "affected", "version": "5.8 kernel", "versionType": "custom"}, {"lessThan": "5.4.0-72.80", "status": "affected", "version": "5.4 kernel", "versionType": "custom"}, {"lessThan": "4.15.0-142.146", "status": "affected", "version": "4.15 kernel", "versionType": "custom"}, {"lessThan": "4.4.0-209.241", "status": "affected", "version": "4.4 kernel", "versionType": "custom"}]}], "credits": [{"lang": "en", "value": "An independent security researcher reporting to the SSD Secure Disclosure program"}], "datePublic": "2021-04-15T00:00:00", "descriptions": [{"lang": "en", "value": "The overlayfs implementation in the linux kernel did not properly validate with respect to user namespaces the setting of file capabilities on files in an underlying file system. Due to the combination of unprivileged user namespaces along with a patch carried in the Ubuntu kernel to allow unprivileged overlay mounts, an attacker could use this to gain elevated privileges."}], "metrics": [{"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 8.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "CHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H", "version": "3.1"}}], "problemTypes": [{"descriptions": [{"cweId": "CWE-270", "description": "CWE-270: Privilege Context Switching Error", "lang": "en", "type": "CWE"}]}], "providerMetadata": {"dateUpdated": "2021-12-03T19:06:06", "orgId": "cc1ad9ee-3454-478d-9317-d3e869d708bc", "shortName": "canonical"}, "references": [{"tags": ["x_refsource_MISC"], "url": "https://ubuntu.com/security/notices/USN-4917-1"}, {"tags": ["x_refsource_MISC"], "url": "https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7c03e2cda4a584cadc398e8f6641ca9988a39d52"}, {"tags": ["x_refsource_MISC"], "url": "https://www.openwall.com/lists/oss-security/2021/04/16/1"}, {"tags": ["x_refsource_MISC"], "url": "http://packetstormsecurity.com/files/162434/Kernel-Live-Patch-Security-Notice-LSN-0076-1.html"}, {"tags": ["x_refsource_MISC"], "url": "http://packetstormsecurity.com/files/162866/Ubuntu-OverlayFS-Local-Privilege-Escalation.html"}, {"tags": ["x_refsource_MISC"], "url": "http://packetstormsecurity.com/files/165151/Ubuntu-Overlayfs-Local-Privilege-Escalation.html"}], "solutions": [{"lang": "en", "value": "Apply https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7c03e2cda4a584cadc398e8f6641ca9988a39d52"}], "source": {"discovery": "EXTERNAL"}, "workarounds": [{"lang": "en", "value": "Disable unprivileged user namespaces."}], "x_generator": {"engine": "Vulnogram 0.0.9"}, "x_legacyV4Record": {"CVE_data_meta": {"ASSIGNER": "security@ubuntu.com", "DATE_PUBLIC": "2021-04-15T00:00:00.000Z", "ID": "CVE-2021-3493", "STATE": "PUBLIC"}, "affects": {"vendor": {"vendor_data": [{"product": {"product_data": [{"product_name": "linux kernel", "version": {"version_data": [{"version_affected": "<", "version_name": "5.8 kernel", "version_value": "5.8.0-50.56"}, {"version_affected": "<", "version_name": "5.4 kernel", "version_value": "5.4.0-72.80"}, {"version_affected": "<", "version_name": "4.15 kernel", "version_value": "4.15.0-142.146"}, {"version_affected": "<", "version_name": "4.4 kernel", "version_value": "4.4.0-209.241"}]}}]}, "vendor_name": "Ubuntu"}]}}, "credit": [{"lang": "eng", "value": "An independent security researcher reporting to the SSD Secure Disclosure program"}], "data_format": "MITRE", "data_type": "CVE", "data_version": "4.0", "description": {"description_data": [{"lang": "eng", "value": "The overlayfs implementation in the linux kernel did not properly validate with respect to user namespaces the setting of file capabilities on files in an underlying file system. Due to the combination of unprivileged user namespaces along with a patch carried in the Ubuntu kernel to allow unprivileged overlay mounts, an attacker could use this to gain elevated privileges."}]}, "generator": {"engine": "Vulnogram 0.0.9"}, "impact": {"cvss": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 8.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "CHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H", "version": "3.1"}}, "problemtype": {"problemtype_data": [{"description": [{"lang": "eng", "value": "CWE-270: Privilege Context Switching Error"}]}]}, "references": {"reference_data": [{"name": "https://ubuntu.com/security/notices/USN-4917-1", "refsource": "MISC", "url": "https://ubuntu.com/security/notices/USN-4917-1"}, {"name": "https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7c03e2cda4a584cadc398e8f6641ca9988a39d52", "refsource": "MISC", "url": "https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7c03e2cda4a584cadc398e8f6641ca9988a39d52"}, {"name": "https://www.openwall.com/lists/oss-security/2021/04/16/1", "refsource": "MISC", "url": "https://www.openwall.com/lists/oss-security/2021/04/16/1"}, {"name": "http://packetstormsecurity.com/files/162434/Kernel-Live-Patch-Security-Notice-LSN-0076-1.html", "refsource": "MISC", "url": "http://packetstormsecurity.com/files/162434/Kernel-Live-Patch-Security-Notice-LSN-0076-1.html"}, {"name": "http://packetstormsecurity.com/files/162866/Ubuntu-OverlayFS-Local-Privilege-Escalation.html", "refsource": "MISC", "url": "http://packetstormsecurity.com/files/162866/Ubuntu-OverlayFS-Local-Privilege-Escalation.html"}, {"name": "http://packetstormsecurity.com/files/165151/Ubuntu-Overlayfs-Local-Privilege-Escalation.html", "refsource": "MISC", "url": "http://packetstormsecurity.com/files/165151/Ubuntu-Overlayfs-Local-Privilege-Escalation.html"}]}, "solution": [{"lang": "en", "value": "Apply https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7c03e2cda4a584cadc398e8f6641ca9988a39d52"}], "source": {"discovery": "EXTERNAL"}, "work_around": [{"lang": "en", "value": "Disable unprivileged user namespaces."}]}}, "adp": [{"providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-03T16:53:17.827Z"}, "title": "CVE Program Container", "references": [{"tags": ["x_refsource_MISC", "x_transferred"], "url": "https://ubuntu.com/security/notices/USN-4917-1"}, {"tags": ["x_refsource_MISC", "x_transferred"], "url": "https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7c03e2cda4a584cadc398e8f6641ca9988a39d52"}, {"tags": ["x_refsource_MISC", "x_transferred"], "url": "https://www.openwall.com/lists/oss-security/2021/04/16/1"}, {"tags": ["x_refsource_MISC", "x_transferred"], "url": "http://packetstormsecurity.com/files/162434/Kernel-Live-Patch-Security-Notice-LSN-0076-1.html"}, {"tags": ["x_refsource_MISC", "x_transferred"], "url": "http://packetstormsecurity.com/files/162866/Ubuntu-OverlayFS-Local-Privilege-Escalation.html"}, {"tags": ["x_refsource_MISC", "x_transferred"], "url": "http://packetstormsecurity.com/files/165151/Ubuntu-Overlayfs-Local-Privilege-Escalation.html"}]}]}, "cveMetadata": {"assignerOrgId": "cc1ad9ee-3454-478d-9317-d3e869d708bc", "assignerShortName": "canonical", "cveId": "CVE-2021-3493", "datePublished": "2021-04-17T04:20:16.706839Z", "dateReserved": "2021-04-12T00:00:00", "dateUpdated": "2024-09-17T02:48:12.994Z", "state": "PUBLISHED"}, "dataType": "CVE_RECORD", "dataVersion": "5.1"}

{}

{"cisaActionDue": "2022-11-10", "cisaExploitAdd": "2022-10-20", "cisaRequiredAction": "Apply updates per vendor instructions.", "cisaVulnerabilityName": "Linux Kernel Privilege Escalation Vulnerability", "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:canonical:ubuntu_linux:*:*:*:*:lts:*:*:*", "matchCriteriaId": "90A80DE7-3EFA-464C-9D31-C46521FFBFBF", "versionEndExcluding": "18.04", "vulnerable": true}, {"criteria": "cpe:2.3:o:canonical:ubuntu_linux:*:*:*:*:lts:*:*:*", "matchCriteriaId": "2027773B-26DA-408E-B71D-40D05690D9EA", "versionEndExcluding": "20.04", "versionStartIncluding": "18.04.1", "vulnerable": true}], "negate": false, "operator": "OR"}]}, {"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:canonical:ubuntu_linux:*:*:*:*:-:*:*:*", "matchCriteriaId": "ACAB2EE0-EC21-4669-840F-94F6C3028C64", "versionEndExcluding": "20.10", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "descriptions": [{"lang": "en", "value": "The overlayfs implementation in the linux kernel did not properly validate with respect to user namespaces the setting of file capabilities on files in an underlying file system. Due to the combination of unprivileged user namespaces along with a patch carried in the Ubuntu kernel to allow unprivileged overlay mounts, an attacker could use this to gain elevated privileges."}, {"lang": "es", "value": "La implementaci\u00f3n de overlayfs en el kernel de Linux no comprob\u00f3 apropiadamente con respecto a los espacios de nombre de los usuarios, la configuraci\u00f3n de las capacidades de los archivos en un sistema de archivos subyacente.&#xa0;Debido a la combinaci\u00f3n de los espacios de nombre de usuarios no privilegiados junto con un parche incluido en el kernel de Ubuntu para permitir montajes de superposici\u00f3n no privilegiados, un atacante podr\u00eda usar esto para alcanzar privilegios elevados"}], "id": "CVE-2021-3493", "lastModified": "2024-11-21T06:21:40.433", "metrics": {"cvssMetricV2": [{"acInsufInfo": false, "baseSeverity": "HIGH", "cvssData": {"accessComplexity": "LOW", "accessVector": "LOCAL", "authentication": "NONE", "availabilityImpact": "COMPLETE", "baseScore": 7.2, "confidentialityImpact": "COMPLETE", "integrityImpact": "COMPLETE", "vectorString": "AV:L/AC:L/Au:N/C:C/I:C/A:C", "version": "2.0"}, "exploitabilityScore": 3.9, "impactScore": 10.0, "obtainAllPrivilege": false, "obtainOtherPrivilege": false, "obtainUserPrivilege": false, "source": "nvd@nist.gov", "type": "Primary", "userInteractionRequired": false}], "cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 8.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "CHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 2.0, "impactScore": 6.0, "source": "security@ubuntu.com", "type": "Secondary"}, {"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.9, "source": "nvd@nist.gov", "type": "Primary"}]}, "published": "2021-04-17T05:15:14.630", "references": [{"source": "security@ubuntu.com", "tags": ["Exploit", "Third Party Advisory", "VDB Entry"], "url": "http://packetstormsecurity.com/files/162434/Kernel-Live-Patch-Security-Notice-LSN-0076-1.html"}, {"source": "security@ubuntu.com", "tags": ["Third Party Advisory", "VDB Entry"], "url": "http://packetstormsecurity.com/files/162866/Ubuntu-OverlayFS-Local-Privilege-Escalation.html"}, {"source": "security@ubuntu.com", "tags": ["Exploit", "Third Party Advisory", "VDB Entry"], "url": "http://packetstormsecurity.com/files/165151/Ubuntu-Overlayfs-Local-Privilege-Escalation.html"}, {"source": "security@ubuntu.com", "tags": ["Mailing List", "Patch", "Third Party Advisory"], "url": "https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7c03e2cda4a584cadc398e8f6641ca9988a39d52"}, {"source": "security@ubuntu.com", "tags": ["Vendor Advisory"], "url": "https://ubuntu.com/security/notices/USN-4917-1"}, {"source": "security@ubuntu.com", "tags": ["Mailing List", "Third Party Advisory"], "url": "https://www.openwall.com/lists/oss-security/2021/04/16/1"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Exploit", "Third Party Advisory", "VDB Entry"], "url": "http://packetstormsecurity.com/files/162434/Kernel-Live-Patch-Security-Notice-LSN-0076-1.html"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Third Party Advisory", "VDB Entry"], "url": "http://packetstormsecurity.com/files/162866/Ubuntu-OverlayFS-Local-Privilege-Escalation.html"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Exploit", "Third Party Advisory", "VDB Entry"], "url": "http://packetstormsecurity.com/files/165151/Ubuntu-Overlayfs-Local-Privilege-Escalation.html"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Mailing List", "Patch", "Third Party Advisory"], "url": "https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7c03e2cda4a584cadc398e8f6641ca9988a39d52"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Vendor Advisory"], "url": "https://ubuntu.com/security/notices/USN-4917-1"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Mailing List", "Third Party Advisory"], "url": "https://www.openwall.com/lists/oss-security/2021/04/16/1"}], "sourceIdentifier": "security@ubuntu.com", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-270"}], "source": "security@ubuntu.com", "type": "Secondary"}, {"description": [{"lang": "en", "value": "CWE-863"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{"bugzilla": {"description": "kernel: overlayfs file system caps privilege escalation", "id": "1950506", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1950506"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.4", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-552", "details": ["The overlayfs implementation in the linux kernel did not properly validate with respect to user namespaces the setting of file capabilities on files in an underlying file system. Due to the combination of unprivileged user namespaces along with a patch carried in the Ubuntu kernel to allow unprivileged overlay mounts, an attacker could use this to gain elevated privileges.", "A flaw was found in the Linux kernel. The overlayfs stacking file system does not properly validate the application of file capabilities against user namespaces. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability."], "name": "CVE-2021-3493", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:5", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 5"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-alt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2021-04-16T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2021-3493\nhttps://nvd.nist.gov/vuln/detail/CVE-2021-3493\nhttps://www.cisa.gov/known-exploited-vulnerabilities-catalog"], "threat_severity": "Moderate"}