VulnerabilityDeferred

CVE-2025-63235

This behavior allows an attacker to create numerous half-open connections that consume memory and file descriptors indefinitely, potentially triggering the Linux OOM killer and causing a denial of service.

HIGH 7.5EPSS 0.32%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.32%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

In sol commit 373d848 (2024-12-12), the broker does not fully release resources when handling malformed or duplicate CONNECT packets. When clients send invalid CONNECT packets - either due to repeated attempts or failed authentication - the server may silently drop the connection or send a CONNACK but fail to close the session or deallocate internal resources. This behavior allows an attacker to create numerous half-open connections that consume memory and file descriptors indefinitely, potentially triggering the Linux OOM killer and causing a denial of service.

CVSS 3.1: 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS: 0.32% probability · 25th percentile
CISA KEV: Not listed
Weakness: CWE-400
Source: cve@mitre.org

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.