Vulnerability identifier: #VU9823

Vulnerability risk: Low

CVSSv3.1: 6.8 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: N/A

CWE-ID: CWE-264

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
NetBSD
Operating systems & Components / Operating system

Vendor: NetBSD Foundation, Inc

Description
The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to an error in compat_linux32 when handling GDT on amd64 system in sys/compat/linux32/arch/amd64/linux32_machdep.c. A local unprivileged user can create a condition where a page fault is generated if a segment register is reloaded with a "high" selector, located near the end of the GDT, and gain root access to the system.

Mitigation
Install update from vendor's website.

Vulnerable software versions

NetBSD: 6.0 - 7.1

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External links
http://ftp.netbsd.org/pub/NetBSD/security/advisories/NetBSD-SA2018-001.txt.asc

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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.