AI description
CVE-2025-66624 affects the BACnet Protocol Stack library before version 1.5.0.rc2. The vulnerability lies in the `npdu_is_expected_reply` function within `src/bacnet/npdu.c`, where it indexes `request_pdu[offset+2/3/5]` and `reply_pdu[offset+1/2/4]` without validating the existence of the APDU bytes. Specifically, the `bacnet_npdu_decode()` function can return an offset of 2 for a 2-byte NPDU, causing tiny PDUs to bypass the version check and subsequently be read out of bounds. Exploitation of this vulnerability could lead to a crash (DoS) on ASan/MPU/strict builds. The attack has low complexity, requires no privileges, and needs no user interaction.
- Description
- 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 npdu_is_expected_reply function in src/bacnet/npdu.c indexes request_pdu[offset+2/3/5] and reply_pdu[offset+1/2/4] without verifying that those APDU bytes exist. bacnet_npdu_decode() 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.
- Source
- security-advisories@github.com
- NVD status
- Received
CVSS 3.1
- Type
- Secondary
- Base score
- 7.5
- Impact score
- 3.6
- Exploitability score
- 3.9
- Vector string
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Severity
- HIGH
- security-advisories@github.com
- CWE-125
Hype score is a measure of social media activity compared against trending CVEs from the past 12 months. Max score 100.
- Hype score
6