#VU99771 Security restrictions bypass in Linux kernel - CVE-2020-16120

Vulnerability identifier: #VU99771

Vulnerability risk: Low

CVSSv4.0: 4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2020-16120

CWE-ID: CWE-264

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
Linux kernel
Operating systems & Components / Operating system

Vendor: Linux Foundation

Description

The vulnerability allows a local privileged user to gain access to sensitive information.

The vulnerability exists due to security restrictions bypass error within the ovl_open_realfile() and ovl_change_flags() functions in fs/overlayfs/file.c. A local privileged user can gain access to sensitive information.

Mitigation
Install update from vendor's repository.

Vulnerable software versions

Linux kernel: 5.8 rc1, 5.8 rc2, 5.8 rc3, 5.8 rc4, 5.8 rc5, 5.8 rc6

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External links
https://git.kernel.org/linus/b6650dab404c701d7fe08a108b746542a934da84
https://launchpad.net/bugs/1894980
https://ubuntu.com/USN-4578-1
https://www.openwall.com/lists/oss-security/2020/10/14/2
https://launchpad.net/bugs/1900141
https://ubuntu.com/USN-4576-1
https://git.kernel.org/linus/56230d956739b9cb1cbde439d76227d77979a04d
https://git.kernel.org/linus/d1d04ef8572bc8c22265057bd3d5a79f223f8f52
https://ubuntu.com/USN-4577-1
https://git.kernel.org/linus/48bd024b8a40d73ad6b086de2615738da0c7004f
https://git.kernel.org/linus/05acefb4872dae89e772729efb194af754c877e8
https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.8

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Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.