#VU16060 Security restrictions bypass in Linux kernel - CVE-2018-16862

Vulnerability identifier: #VU16060

Vulnerability risk: Low

CVSSv4.0: 1.1 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2018-16862

CWE-ID: CWE-20

Exploitation vector: Local

Exploit availability: No

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

Vendor: Linux Foundation

Description

The vulnerability allows a local attacker to bypass security restrictions on the target system.

The vulnerability exists due to an error when the cleancache subsystem clears an inode after the final file truncation (removal). A local attacker can supply new file created with the same inode that may contain leftover pages from cleancache and bypass security restrictions to conduct further attacks.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Linux kernel: 4.15.0 rc4 - 4.19.3

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External links
https://bugzilla.redhat.com/show_bug.cgi?id=1649017
https://lore.kernel.org/patchwork/patch/1011367/

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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.