Vulnerability identifier: #VU6650

Vulnerability risk: Low

CVSSv3.1: 4.6 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L/E:U/RL:O/RC:C]

CVE-ID: CVE-2017-5669

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 attacker to bypass security restriction on the target system.

The weakness exists in the do_shmat function in ipc/shm.c due to improper restriction of the address calculated by a certain rounding operation. A local attacker can map page zero, and consequently bypass a protection mechanism that exists for the mmap system call, by making crafted shmget and shmat system calls in a privileged context.

Mitigation
Update to version 4.9.13 or later.

Vulnerable software versions

Linux kernel: 4.9 - 4.9.12

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External links
http://github.com/torvalds/linux/commit/e1d35d4dc7f089e6c9c080d556feedf9c706f0c7

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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.