CVE-2021-46952

2024-02-2700:00:00

ubuntu.com

linux

kernel

nfs

vulnerability

out-of-bounds

udp

retrans

validation

7.1 High

CVSS3

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

NONE

Availability Impact

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

6.5 Medium

AI Score

Confidence

High

0.0004 Low

EPSS

Percentile

5.1%

JSON

In the Linux kernel, the following vulnerability has been resolved: NFS:
fs_context: validate UDP retrans to prevent shift out-of-bounds Fix shift
out-of-bounds in xprt_calc_majortimeo(). This is caused by a garbage
timeout (retrans) mount option being passed to nfs mount, in this case from
syzkaller. If the protocol is XPRT_TRANSPORT_UDP, then ‘retrans’ is a shift
value for a 64-bit long integer, so ‘retrans’ cannot be >= 64. If it is >=
64, fail the mount and return an error.