جزئیات آسیب‌پذیری

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.

• https://github.com/bacnet-stack/bacnet-stack/security/advisories/GHSA-8wgw-5h6x-qgqg x_refsource_CONFIRM
• https://github.com/bacnet-stack/bacnet-stack/commit/9378f7d1e70169ebde4a5090bae7603703eadf48 x_refsource_MISC