CVE-2020-16120

{"cve": {"data_type": "CVE", "references": {"reference_data": [{"url": "https://git.kernel.org/linus/b6650dab404c701d7fe08a108b746542a934da84", "name": "https://git.kernel.org/linus/b6650dab404c701d7fe08a108b746542a934da84", "tags": ["Patch", "Third Party Advisory"], "refsource": "CONFIRM"}, {"url": "https://launchpad.net/bugs/1894980", "name": "https://launchpad.net/bugs/1894980", "tags": ["Issue Tracking", "Patch", "Third Party Advisory"], "refsource": "UBUNTU"}, {"url": "https://ubuntu.com/USN-4578-1", "name": "https://ubuntu.com/USN-4578-1", "tags": ["Third Party Advisory"], "refsource": "UBUNTU"}, {"url": "https://www.openwall.com/lists/oss-security/2020/10/14/2", "name": "https://www.openwall.com/lists/oss-security/2020/10/14/2", "tags": ["Mailing List", "Third Party Advisory"], "refsource": "CONFIRM"}, {"url": "https://launchpad.net/bugs/1900141", "name": "https://launchpad.net/bugs/1900141", "tags": ["Issue Tracking", "Third Party Advisory"], "refsource": "UBUNTU"}, {"url": "https://ubuntu.com/USN-4576-1", "name": "https://ubuntu.com/USN-4576-1", "tags": ["Third Party Advisory"], "refsource": "UBUNTU"}, {"url": "https://git.kernel.org/linus/56230d956739b9cb1cbde439d76227d77979a04d", "name": "https://git.kernel.org/linus/56230d956739b9cb1cbde439d76227d77979a04d", "tags": ["Patch", "Third Party Advisory"], "refsource": "CONFIRM"}, {"url": "https://git.kernel.org/linus/d1d04ef8572bc8c22265057bd3d5a79f223f8f52", "name": "https://git.kernel.org/linus/d1d04ef8572bc8c22265057bd3d5a79f223f8f52", "tags": ["Patch", "Third Party Advisory"], "refsource": "CONFIRM"}, {"url": "https://ubuntu.com/USN-4577-1", "name": "https://ubuntu.com/USN-4577-1", "tags": ["Third Party Advisory"], "refsource": "UBUNTU"}, {"url": "https://git.kernel.org/linus/48bd024b8a40d73ad6b086de2615738da0c7004f", "name": "https://git.kernel.org/linus/48bd024b8a40d73ad6b086de2615738da0c7004f", "tags": ["Patch", "Third Party Advisory"], "refsource": "CONFIRM"}, {"url": "https://git.kernel.org/linus/05acefb4872dae89e772729efb194af754c877e8", "name": "https://git.kernel.org/linus/05acefb4872dae89e772729efb194af754c877e8", "tags": ["Patch", "Third Party Advisory"], "refsource": "CONFIRM"}]}, "data_format": "MITRE", "description": {"description_data": [{"lang": "en", "value": "Overlayfs did not properly perform permission checking when copying up files in an overlayfs and could be exploited from within a user namespace, if, for example, unprivileged user namespaces were allowed. It was possible to have a file not readable by an unprivileged user to be copied to a mountpoint controlled by the user, like a removable device. This was introduced in kernel version 4.19 by commit d1d04ef (\"ovl: stack file ops\"). This was fixed in kernel version 5.8 by commits 56230d9 (\"ovl: verify permissions in ovl_path_open()\"), 48bd024 (\"ovl: switch to mounter creds in readdir\") and 05acefb (\"ovl: check permission to open real file\"). Additionally, commits 130fdbc (\"ovl: pass correct flags for opening real directory\") and 292f902 (\"ovl: call secutiry hook in ovl_real_ioctl()\") in kernel 5.8 might also be desired or necessary. These additional commits introduced a regression in overlay mounts within user namespaces which prevented access to files with ownership outside of the user namespace. This regression was mitigated by subsequent commit b6650da (\"ovl: do not fail because of O_NOATIMEi\") in kernel 5.11."}]}, "problemtype": {"problemtype_data": [{"description": [{"lang": "en", "value": "NVD-CWE-Other"}]}]}, "data_version": "4.0", "CVE_data_meta": {"ID": "CVE-2020-16120", "ASSIGNER": "security@ubuntu.com"}}, "impact": {"baseMetricV2": {"cvssV2": {"version": "2.0", "baseScore": 2.1, "accessVector": "LOCAL", "vectorString": "AV:L/AC:L/Au:N/C:P/I:N/A:N", "authentication": "NONE", "integrityImpact": "NONE", "accessComplexity": "LOW", "availabilityImpact": "NONE", "confidentialityImpact": "PARTIAL"}, "severity": "LOW", "acInsufInfo": false, "impactScore": 2.9, "obtainAllPrivilege": false, "exploitabilityScore": 3.9, "obtainUserPrivilege": false, "obtainOtherPrivilege": false, "userInteractionRequired": false}, "baseMetricV3": {"cvssV3": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 4.4, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "HIGH", "confidentialityImpact": "HIGH"}, "impactScore": 3.6, "exploitabilityScore": 0.8}}, "publishedDate": "2021-02-10T20:15Z", "configurations": {"nodes": [{"children": [], "operator": "OR", "cpe_match": [{"cpe23Uri": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "cpe_name": [], "vulnerable": true, "versionEndExcluding": "5.11"}]}, {"children": [], "operator": "OR", "cpe_match": [{"cpe23Uri": "cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:esm:*:*:*", "cpe_name": [], "vulnerable": true}, {"cpe23Uri": "cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*", "cpe_name": [], "vulnerable": true}, {"cpe23Uri": "cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*", "cpe_name": [], "vulnerable": true}, {"cpe23Uri": "cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:*", "cpe_name": [], "vulnerable": true}]}], "CVE_data_version": "4.0"}, "lastModifiedDate": "2021-11-18T18:40Z"}