Executive Summary
Informations | |||
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Name | CVE-2020-16120 | First vendor Publication | 2021-02-10 |
Vendor | Cve | Last vendor Modification | 2021-02-18 |
Security-Database Scoring CVSS v3
Cvss vector : CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N | |||
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Overall CVSS Score | 4.4 | ||
Base Score | 4.4 | Environmental Score | 4.4 |
impact SubScore | 3.6 | Temporal Score | 4.4 |
Exploitabality Sub Score | 0.8 | ||
Attack Vector | Local | Attack Complexity | Low |
Privileges Required | High | User Interaction | None |
Scope | Unchanged | Confidentiality Impact | High |
Integrity Impact | None | Availability Impact | None |
Calculate full CVSS 3.0 Vectors scores |
Security-Database Scoring CVSS v2
Cvss vector : (AV:L/AC:L/Au:N/C:P/I:N/A:N) | |||
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Cvss Base Score | 2.1 | Attack Range | Local |
Cvss Impact Score | 2.9 | Attack Complexity | Low |
Cvss Expoit Score | 3.9 | Authentication | None Required |
Calculate full CVSS 2.0 Vectors scores |
Detail
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. |
Original Source
Url : http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-16120 |
CWE : Common Weakness Enumeration
% | Id | Name |
---|---|---|
100 % | CWE-269 | Improper Privilege Management |
CPE : Common Platform Enumeration
Sources (Detail)
Alert History
Date | Informations |
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2021-03-27 01:33:39 |
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2021-02-18 21:23:22 |
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2021-02-11 00:22:50 |
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