CVE-2025-66624: BACnet-stack MS/TP reply matcher OOB read
BACnet Protocol Stack library provides a BACnet application layer, network layer and media access (MAC) layer communications services. Prior to 1.5.0.rc2, The npduisexpectedreply function in src/bacnet/npdu.c indexes requestpdu[offset+2/3/5] and replypdu[offset+1/2/4] without verifying that those APDU bytes exist. bacnetnpdudecode() can return offset == 2 for a 2-byte NPDU, so tiny PDUs pass the version check and then get read out of bounds. On ASan/MPU/strict builds this is an immediate crash (DoS). On unprotected builds it is undefined behavior and can mis-route replies; RCE is unlikely because only reads occur, but DoS is reliable.
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2025-66624?
CVE-2025-66624 is considered to have a high severity due to the potential for denial of service and data corruption.
How do I fix CVE-2025-66624?
To fix CVE-2025-66624, upgrade to bacnet-stack version 1.5.0.rc2 or later.
What components are affected by CVE-2025-66624?
CVE-2025-66624 affects the BACnet Protocol Stack library up to version 1.5.0.rc2.
What is the nature of the vulnerability in CVE-2025-66624?
CVE-2025-66624 involves improper indexing that can lead to unexpected behavior in BACnet communications.
Is CVE-2025-66624 remotely exploitable?
Yes, CVE-2025-66624 is potentially remotely exploitable due to its nature within the BACnet Protocol.