CVE-2020-16120

Katalog CVE

CVSS 4.4 · Medium EPSS 0,41%

Kerentanan Incorrect Privilege Assignment pada linux kernel, canonical ubuntu linux. Skor CVSS 3.1 4.4 (Medium) menurut NVD.

Deskripsi (NVD)

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.

Rincian

Terbit di NVD

10 Februari 2021

Terakhir diubah

17 Juni 2026

Status NVD

Modified

CVSS 3.1

4.4 (Medium), sumber NVD
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N · uraikan di kalkulator

Jenis kelemahan (CWE)

CWE-266: Incorrect Privilege Assignment

EPSS (30 hari)

0,41% peluang dieksploitasi; lebih tinggi dari 33,6% CVE lain

Produk dan versi terdampak

> Data dari konfigurasi CPE di NVD.

Referensi dan perbaikan

• https://git.kernel.org/linus/05acefb4872dae89e772729efb194af754c877e8 patch · advisory pihak ketiga
• https://git.kernel.org/linus/48bd024b8a40d73ad6b086de2615738da0c7004f patch · advisory pihak ketiga
• https://git.kernel.org/linus/56230d956739b9cb1cbde439d76227d77979a04d patch · advisory pihak ketiga
• https://git.kernel.org/linus/b6650dab404c701d7fe08a108b746542a934da84 patch · advisory pihak ketiga
• https://git.kernel.org/linus/d1d04ef8572bc8c22265057bd3d5a79f223f8f52 patch · advisory pihak ketiga
• https://launchpad.net/bugs/1894980 issue tracking · patch · advisory pihak ketiga
• https://launchpad.net/bugs/1900141 issue tracking · advisory pihak ketiga
• https://ubuntu.com/USN-4576-1 advisory pihak ketiga
• https://ubuntu.com/USN-4577-1 advisory pihak ketiga
• https://ubuntu.com/USN-4578-1 advisory pihak ketiga
• https://www.openwall.com/lists/oss-security/2020/10/14/2 mailing list · advisory pihak ketiga