Denial of service in Linux kernel NFS subsystem

Published: 2021-10-07

Risk	Low
Patch available	YES
Number of vulnerabilities	1
CVE-ID	CVE-2021-38201
CWE-ID	CWE-125
Exploitation vector	Network
Public exploit	N/A
Vulnerable software Subscribe	Linux kernel Operating systems & Components / Operating system
Vendor

Security Bulletin

This security bulletin contains one low risk vulnerability.

1) Out-of-bounds read

EUVDB-ID: #VU57137

Risk: Low

CVSSv3.1: 3.8 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-38201

CWE-ID: CWE-125 - Out-of-bounds read

Exploit availability: No

Description

The vulnerability allows a remote user to perform a denial of service (DoS) attack.

The vulnerability exists due to a boundary error within the net/sunrpc/xdr.c in the Linux kernel. A remote user can perform multiple NFS 4.2 READ_PLUS operations and cause a denial of service attack.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Linux kernel: before 5.13.4

External links

http://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.13.4
http://github.com/torvalds/linux/commit/6d1c0f3d28f98ea2736128ed3e46821496dc3a8c
http://security.netapp.com/advisory/ntap-20210902-0010/

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

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