Information disclosure in FreeBSD NFS client

1) State Issues

EUVDB-ID: #VU84346

Risk: Low

CVSSv3.1: 3.3 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2023-6660

CWE-ID: CWE-371 - State Issues

Exploit availability: No

Description

The vulnerability allows a local user to gain access to sensitive information.

The vulnerability exists due to an error within the NFS client when appending data to file on an network share. When a program running on an affected system appends data to a file via an NFS client mount, the bug can cause the NFS client to fail to copy in the data to be written but proceed as though the copy operation had succeeded. This means that the data to be written is instead replaced with whatever data had been in the packet buffer previously. 

An unprivileged user with access to an affected system may abuse the bug to trigger disclosure of sensitive information.  In particular, the leak is limited to data previously stored in mbufs, which are used for network transmission and reception, and for certain types of inter-process communication.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

FreeBSD: 13.0 - 14.0

External links

http://www.freebsd.org/security/advisories/FreeBSD-SA-23:18.nfsclient.asc

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.