CVE-2023-5871
libnbd: Malicious NBD server may crash libnbd
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · November 1, 2023
Updated · November 21, 2025
Description
A flaw was found in libnbd, due to a malicious Network Block Device (NBD), a protocol for accessing Block Devices such as hard disks over a Network. This issue may allow a malicious NBD server to cause a Denial of Service.
Statement
Libnbd 1.16.x and earlier are not impacted, these versions gracefully reject an extended response from a malicious server as unknown since they lack extended headers support.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
CVSS / CWE
CVSS 3.1 · 5.3CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
CWE-617 · Reachable Assertion