CVE-2023-5215 MEDIUM

CVE-2023-5215: Libnbd: crash or misbehaviour when nbd server returns an unexpected block size

Vendor Red Hat
Product Red Hat Enterprise Linux 8
Weakness CWE-241
Published September 28, 2023
Last update November 8, 2025
View on NVD All CVEs

CVSS base score

5.3/10
Attack vector Adjacent
Attack complexity High
Privileges required None
User interaction None
Confidentiality None
Integrity None

CVSS vector

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

What the vulnerability does

01Description

A flaw was found in libnbd. A server can reply with a block size larger than 2^63 (the NBD spec states the size is a 64-bit unsigned value). This issue could lead to an application crash or other unintended behavior for NBD clients that doesn't treat the return value of the nbd_get_size() function correctly.

Key dates

02Disclosure timeline

September 28, 2023 CVE published
November 8, 2025 Record updated