Out-of-bounds read in Linux kernel NFS support

1) Out-of-bounds read

EUVDB-ID: #VU89262

Risk: Medium

CVSSv3.1: 5.2 [CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-46952

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

Exploit availability: No

Description

The vulnerability allows a remote attacker to gain access to sensitive information.

The vulnerability exists due to a boundary condition within the nfs23_parse_monolithic() function in fs/nfs/fs_context.c when handling UDP retrans. A remote attacker can trigger an out-of-bounds read error and gain access to sensitive information or perform a denial of service (DoS) attack.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Linux kernel: before 5.10.36

External links

http://git.kernel.org/stable/c/96fa26b74cdcf9f5c98996bf36bec9fb5b19ffe2
http://git.kernel.org/stable/c/2f3380121d49e829fb73ba86240c181bc32ad897
http://git.kernel.org/stable/c/3d0163821c035040a46d816a42c0780f0f0a30a8
http://git.kernel.org/stable/c/c09f11ef35955785f92369e25819bf0629df2e59

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.