Vulnerability identifier: #VU7213

Vulnerability risk: Medium

CVSSv3.1: 7.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2017-8797

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: No

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

Vendor: Linux Foundation

Description
The vulnerability allows a remote attacker to cause DoS condition on the target system.

The weakness exists in the Linux kernel NFSv4 Server due to insufficient validation of user-supplied input. A remote attacker on a system within the target mount's host address mask rang can send a specially crafted NFSv4 pNFS LAYOUTGET command via UDP, trigger an array deference error and cause the system to crash.

Successful exploitation of the vulnerability results in denial of service.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Linux kernel: 4.4.1 - 4.4.26, 4.8.0 - 4.8.12, 4.11.1 - 4.11.5

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External links
http://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/fs/nfsd?h=v4.12-rc7&am...
http://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/fs/nfsd?h=v4.12-rc7&am...

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

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