CVE-2020-16120
published 2021-02-10CVE-2020-16120: 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…
PriorityP418medium4.4CVSS 3.1
AVLACLPRHUINSUCHINAN
EPSS
0.40%
31.9th percentile
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.
Affected
18 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| canonical | ubuntu_linux | — | — |
| canonical | ubuntu_linux | — | — |
| canonical | ubuntu_linux | — | — |
| canonical | ubuntu_linux | — | — |
| debian | linux | < linux 5.8.7-1 (bookworm) | linux 5.8.7-1 (bookworm) |
| linux | linux_kernel | < 5.11 | 5.11 |
| linux | linux_kernel | >= 0 < 5.8.7-1 | 5.8.7-1 |
| linux | linux_kernel | >= 0 < 5.8.7-1 | 5.8.7-1 |
| linux | linux_kernel | >= 0 < 5.8.7-1 | 5.8.7-1 |
| linux | linux_kernel | >= 0 < 5.8.7-1 | 5.8.7-1 |
| linux | linux_kernel | >= 0 < 4.15.0-121.123 | 4.15.0-121.123 |
| linux | linux_kernel | >= 0 < 5.4.0-51.56 | 5.4.0-51.56 |
| linux | linux_kernel | >= 0 < 4.4.0-193.224 | 4.4.0-193.224 |
| linux | linux_kernel | >= 0 < 4.15.0-121.123 | 4.15.0-121.123 |
| linux | linux_kernel | >= 0 < 5.4.0-51.56 | 5.4.0-51.56 |
| linux_kernel | linux_kernel | >= 5.11-stable < 5.11.0 | 5.11.0 |
| msrc | cbl2_kernel_5.10.78.1-1_on_cbl_mariner_2.0 | — | — |
| msrc | cm1_kernel_5.10.60.1-1_on_cbl_mariner_1.0 | — | — |
CVSS provenance
nvdv3.14.4MEDIUMCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N
nvdv2.02.1LOWAV:L/AC:L/Au:N/C:P/I:N/A:N
osv7.8HIGH
vendor_ubuntu6.3MEDIUM
vendor_debian5.1MEDIUM
vendor_redhat5.1MEDIUM
vendor_msrc4.4MEDIUM
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GHSA
GHSA-q6jw-34cj-733v: Overlayfs did not properly perform permission checking when copying up files in an overlayfs and could be exploited from within a user namespace, if,
ghsa_unreviewed·2022-05-24
CVE-2020-16120 [MEDIUM] CWE-269 GHSA-q6jw-34cj-733v: Overlayfs did not properly perform permission checking when copying up files in an overlayfs and could be exploited from within a user namespace, if,
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 k
OSV
CVE-2020-16120: Overlayfs did not properly perform permission checking when copying up files in an overlayfs and could be exploited from within a user namespace, if,
osv·2021-02-10·CVSS 4.4
CVE-2020-16120 [MEDIUM] CVE-2020-16120: Overlayfs did not properly perform permission checking when copying up files in an overlayfs and could be exploited from within a user namespace, if,
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 k
OSV
linux, linux-aws, linux-aws-5.4, linux-azure, linux-azure-5.4, linux-gcp, linux-gcp-5.4, linux-hwe-5.4, linux-kvm, linux-oracle, linux-oracle-5.4, linux-raspi, linux-raspi-5.4 vulnerabilities
osv·2020-10-14·CVSS 5.5
CVE-2020-16119 [MEDIUM] linux, linux-aws, linux-aws-5.4, linux-azure, linux-azure-5.4, linux-gcp, linux-gcp-5.4, linux-hwe-5.4, linux-kvm, linux-oracle, linux-oracle-5.4, linux-raspi, linux-raspi-5.4 vulnerabilities
linux, linux-aws, linux-aws-5.4, linux-azure, linux-azure-5.4, linux-gcp, linux-gcp-5.4, linux-hwe-5.4, linux-kvm, linux-oracle, linux-oracle-5.4, linux-raspi, linux-raspi-5.4 vulnerabilities
Hadar Manor discovered that the DCCP protocol implementation in the Linux
kernel improperly handled socket reuse, leading to a use-after-free
vulnerability. A local attacker could use this to cause a denial of service
(system crash) or possibly execute arbitrary code. (CVE-2020-16119)
Jay Shin discovered that the ext4 file system implementation in the Linux
kernel did not properly handle directory access with broken indexing,
leading to an out-of-bounds read vulnerability. A local attacker could use
this to cause a denial of service (system crash). (CVE-2020-14314)
David Alan Gilbert discovered tha
OSV
Kernel Live Patch Security Notice
osv·2020-10-14·CVSS 4.4
CVE-2020-0067 [MEDIUM] Kernel Live Patch Security Notice
Kernel Live Patch Security Notice
It was discovered that the F2FS file system implementation in the Linux
kernel did not properly perform bounds checking on xattrs in some
situations. A local attacker could possibly use this to expose sensitive
information (kernel memory). (CVE-2020-0067)
It was discovered that the Serial CAN interface driver in the Linux kernel
did not properly initialize data. A local attacker could use this to expose
sensitive information (kernel memory). (CVE-2020-11494)
Mauricio Faria de Oliveira discovered that the aufs implementation in the
Linux kernel improperly managed inode reference counts in the
vfsub_dentry_open() method. A local attacker could use this vulnerability
to cause a denial of service. (CVE-2020-11935)
Piotr Krysiuk discovered that race conditi
OSV
linux-hwe, linux-gke-5.0, linux-gke-5.3, linux-oem-osp1, linux-raspi2-5.3 vulnerabilities
osv·2020-10-14·CVSS 7.8
CVE-2020-16119 [HIGH] linux-hwe, linux-gke-5.0, linux-gke-5.3, linux-oem-osp1, linux-raspi2-5.3 vulnerabilities
linux-hwe, linux-gke-5.0, linux-gke-5.3, linux-oem-osp1, linux-raspi2-5.3 vulnerabilities
Hadar Manor discovered that the DCCP protocol implementation in the Linux
kernel improperly handled socket reuse, leading to a use-after-free
vulnerability. A local attacker could use this to cause a denial of service
(system crash) or possibly execute arbitrary code. (CVE-2020-16119)
Giuseppe Scrivano discovered that the overlay file system in the Linux
kernel did not properly perform permission checks in some situations. A
local attacker could possibly use this to bypass intended restrictions and
gain read access to restricted files. (CVE-2020-16120)
OSV
linux, linux-aws, linux-aws-hwe, linux-azure, linux-azure-4.15, linux-gcp, linux-gcp-4.15, linux-gke-4.15, linux-hwe, linux-kvm, linux-oem, linux-oracle, linux-raspi2, linux-snapdragon vulnerabilities
osv·2020-10-14·CVSS 5.5
CVE-2020-16119 [MEDIUM] linux, linux-aws, linux-aws-hwe, linux-azure, linux-azure-4.15, linux-gcp, linux-gcp-4.15, linux-gke-4.15, linux-hwe, linux-kvm, linux-oem, linux-oracle, linux-raspi2, linux-snapdragon vulnerabilities
linux, linux-aws, linux-aws-hwe, linux-azure, linux-azure-4.15, linux-gcp, linux-gcp-4.15, linux-gke-4.15, linux-hwe, linux-kvm, linux-oem, linux-oracle, linux-raspi2, linux-snapdragon vulnerabilities
Hadar Manor discovered that the DCCP protocol implementation in the Linux
kernel improperly handled socket reuse, leading to a use-after-free
vulnerability. A local attacker could use this to cause a denial of service
(system crash) or possibly execute arbitrary code. (CVE-2020-16119)
Wen Xu discovered that the XFS file system in the Linux kernel did not
properly validate inode metadata in some situations. An attacker could use
this to construct a malicious XFS image that, when mounted, could cause a
denial of service (system crash). (CVE-2018-10322)
It was discovered that the btrfs file s
Microsoft
Unprivileged overlay + shiftfs read access
vendor_msrc·2021-02-09·CVSS 4.4
CVE-2020-16120 [MEDIUM] CWE-266 Unprivileged overlay + shiftfs read access
Unprivileged overlay + shiftfs read access
FAQ: Is Azure Linux the only Microsoft product that includes this open-source library and is therefore potentially affected by this vulnerability?
One of the main benefits to our customers who choose to use the Azure Linux distro is the commitment to keep it up to date with the most recent and most secure versions of the open source libraries with which the distro is composed. Microsoft is committed to transparency in this work which is why we began publishing CSAF/VEX in October 2025. See this blog post for more information. If impact to additional products is identified, we will update the CVE to reflect this.
Mariner: Mariner
canonical: canonical
Customer Action Required: Yes
Remediation: CBL-Mariner Releases
Reference: https://learn.micr
Ubuntu
Linux kernel vulnerabilities
vendor_ubuntu·2020-10-14·CVSS 6.3
CVE-2020-16119 [MEDIUM] Linux kernel vulnerabilities
Title: Linux kernel vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Hadar Manor discovered that the DCCP protocol implementation in the Linux
kernel improperly handled socket reuse, leading to a use-after-free
vulnerability. A local attacker could use this to cause a denial of service
(system crash) or possibly execute arbitrary code. (CVE-2020-16119)
Giuseppe Scrivano discovered that the overlay file system in the Linux
kernel did not properly perform permission checks in some situations. A
local attacker could possibly use this to bypass intended restrictions and
gain read access to restricted files. (CVE-2020-16120)
Instructions: After a standard system update you need to reboot your computer to make
all the necessary changes.
ATTENTION: Due to an u
Ubuntu
Linux kernel vulnerabilities
vendor_ubuntu·2020-10-14·CVSS 5.5
CVE-2020-14314 [MEDIUM] Linux kernel vulnerabilities
Title: Linux kernel vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Hadar Manor discovered that the DCCP protocol implementation in the Linux
kernel improperly handled socket reuse, leading to a use-after-free
vulnerability. A local attacker could use this to cause a denial of service
(system crash) or possibly execute arbitrary code. (CVE-2020-16119)
Jay Shin discovered that the ext4 file system implementation in the Linux
kernel did not properly handle directory access with broken indexing,
leading to an out-of-bounds read vulnerability. A local attacker could use
this to cause a denial of service (system crash). (CVE-2020-14314)
David Alan Gilbert discovered that the XFS file system implementation in
the Linux kernel did not properly perform metadata
Ubuntu
Linux kernel vulnerabilities
vendor_ubuntu·2020-10-14·CVSS 5.5
CVE-2020-26088 [MEDIUM] Linux kernel vulnerabilities
Title: Linux kernel vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Hadar Manor discovered that the DCCP protocol implementation in the Linux
kernel improperly handled socket reuse, leading to a use-after-free
vulnerability. A local attacker could use this to cause a denial of service
(system crash) or possibly execute arbitrary code. (CVE-2020-16119)
Wen Xu discovered that the XFS file system in the Linux kernel did not
properly validate inode metadata in some situations. An attacker could use
this to construct a malicious XFS image that, when mounted, could cause a
denial of service (system crash). (CVE-2018-10322)
It was discovered that the btrfs file system in the Linux kernel contained
a use-after-free vulnerability when merging free space. An atta
Ubuntu
Kernel Live Patch Security Notice
vendor_ubuntu·2020-10-14·CVSS 4.4
CVE-2020-11935 [MEDIUM] Kernel Live Patch Security Notice
Title: Kernel Live Patch Security Notice
Summary: Several security issues were fixed in the kernel.
It was discovered that the F2FS file system implementation in the Linux
kernel did not properly perform bounds checking on xattrs in some
situations. A local attacker could possibly use this to expose sensitive
information (kernel memory). (CVE-2020-0067)
It was discovered that the Serial CAN interface driver in the Linux kernel
did not properly initialize data. A local attacker could use this to expose
sensitive information (kernel memory). (CVE-2020-11494)
Mauricio Faria de Oliveira discovered that the aufs implementation in the
Linux kernel improperly managed inode reference counts in the
vfsub_dentry_open() method. A local attacker could use this vulnerability
to cause a denial of se
Red Hat
kernel: incorrect unprivileged overlayfs permission checking may lead to information disclosure
vendor_redhat·2020-10-13·CVSS 5.1
CVE-2020-16120 [MEDIUM] CWE-1220 kernel: incorrect unprivileged overlayfs permission checking may lead to information disclosure
kernel: incorrect unprivileged overlayfs permission checking may lead to information disclosure
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 fl
Debian
CVE-2020-16120: linux - Overlayfs did not properly perform permission checking when copying up files in ...
vendor_debian·2020·CVSS 5.1
CVE-2020-16120 [MEDIUM] CVE-2020-16120: linux - Overlayfs did not properly perform permission checking when copying up files in ...
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 k
No detection rules found.
No public exploits indexed.
https://git.kernel.org/linus/05acefb4872dae89e772729efb194af754c877e8https://git.kernel.org/linus/48bd024b8a40d73ad6b086de2615738da0c7004fhttps://git.kernel.org/linus/56230d956739b9cb1cbde439d76227d77979a04dhttps://git.kernel.org/linus/b6650dab404c701d7fe08a108b746542a934da84https://git.kernel.org/linus/d1d04ef8572bc8c22265057bd3d5a79f223f8f52https://launchpad.net/bugs/1894980https://launchpad.net/bugs/1900141https://ubuntu.com/USN-4576-1https://ubuntu.com/USN-4577-1https://ubuntu.com/USN-4578-1https://www.openwall.com/lists/oss-security/2020/10/14/2https://git.kernel.org/linus/05acefb4872dae89e772729efb194af754c877e8https://git.kernel.org/linus/48bd024b8a40d73ad6b086de2615738da0c7004fhttps://git.kernel.org/linus/56230d956739b9cb1cbde439d76227d77979a04dhttps://git.kernel.org/linus/b6650dab404c701d7fe08a108b746542a934da84https://git.kernel.org/linus/d1d04ef8572bc8c22265057bd3d5a79f223f8f52https://launchpad.net/bugs/1894980https://launchpad.net/bugs/1900141https://ubuntu.com/USN-4576-1https://ubuntu.com/USN-4577-1https://ubuntu.com/USN-4578-1https://www.openwall.com/lists/oss-security/2020/10/14/2
2021-02-10
Published