CVE-2024-7409
QEMU: Denial of Service via Improper Synchronization in QEMU NBD Server During Socket Closure
Severity
ModerateRed Hat Product Security
CVSS 3.0
Review impact separately from score.
Published · August 2, 2024
Updated · October 9, 2026
Description
A flaw was found in the QEMU NBD Server. This vulnerability allows a denial of service (DoS) attack via improper synchronization during socket closure when a client keeps a socket open as the server is taken offline.
Statement
This issue is classified as Moderate severity rather than Important because it primarily results in a denial of service condition rather than a more crucial impact such as data corruption, unauthorized access, or system compromise. The NULL pointer dereference occurs under specific conditions where the NBD server is stopped before nbd_blockdev_client_closed is called, which leads to a segmentation fault and crash of the QEMU process. However, this scenario is mitigated by the fact that it requires a particular sequence of events involving client connection handling and server shutdown. Additionally, proper network segmentation and the use of secure client connections can further reduce the likelihood of this issue being exploited.
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 3.0 · 7.5CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE-662 · Improper Synchronization