BACnet Stack: malicious ReadPropertyMultiple-ACK with excessive properties causes global-buffer-overflow in ProcessRPMData()

BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to versions 1.4.5, 1.5.1, and 1.6.0, in the official apps/epics client tool on v1.6.0-rc1 (not in the generic BACnet RPM ACK decoder alone) a malicious BACnet/IP endpoint can reply to the EPICS tool’s legitimate ReadPropertyMultiple request with a syntactically valid ReadPropertyMultiple-ACK that contains more heading properties than the tool’s fixed local storage can hold. The response is decoded successfully and later consumed by ProcessRPMData(), which writes property values into a fixed global array using an unbounded linear index. This results in a reproducible global-buffer-overflow in apps/epics/main.c. This is a network-reachable memory corruption in the official epics tool’s response-processing path. The root cause is that apps/epics treats a remotely supplied variable-length RPM property list as if it were a trusted, fixed-size local heading-property set. This issue has been patched in versions 1.4.5, 1.5.1, and 1.6.0.

BACnet Stack: Stack-based buffer overflow in Notification Class RemoveListElement recipient-list decoding

BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to versions 1.4.4, 1.5.1, and 1.6.0, a RemoveListElement request targeting Notification-Class.recipient-list can trigger a stack-based out-of-bounds write in the current master branch when the request contains more than NC_MAX_RECIPIENTS valid BACnetDestination elements. This issue has been patched in versions 1.4.4, 1.5.1, and 1.6.0.

BACnet Stack: Stack buffer overflow in Loop internal ReadProperty path via Life_Safety_Zone.accepted-modes on the default BACnet/IP server

BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to versions 1.4.4, 1.5.1, and 1.6.0, the current master demo server can be crashed remotely over BACnet/IP by sending a valid Confirmed WriteProperty request that updates loop-1's controlled-variable-reference to point to life-safety-zone-1 / accepted-modes. This issue has been patched in versions 1.4.4, 1.5.1, and 1.6.0.

Atomic-Read-File RecordCount Stack-Based Out-of-Bounds Write in bacnet-stack

BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to versions 1.4.4 and 1.5.1, there is a stack-based out-of-bounds write / stack-buffer-overflow in bacnet-stack when the server processes a malicious Atomic-Read-File request in record access mode. The bug is triggered on the real server side. A crafted request can set an excessively large RecordCount, which is later used as the loop bound for writing record data into a stack-allocated BACNET_ATOMIC_READ_FILE_DATA data structure. However, the stack object only has space for one fileData element. When the loop reaches i = 1, the code computes &data->fileData[1], which is already out of bounds, and the resulting invalid pointer is passed down to memmove(), causing a stack-buffer-overflow. This issue has been patched in versions 1.4.4 and 1.5.1.

BACnet Stack: NULL pointer dereference in bacnet_device_object_reference_decode() when WriteProperty updates Structured View subordinate-list

BACnet Stack is a BACnet open source protocol stack C library for embedded systems. From versions 1.4.0 to before 1.4.4, and 1.5.0 to before 1.5.1, a NULL pointer dereference can be triggered in bacnet_device_object_reference_decode() when a WriteProperty request updates OBJECT_STRUCTURED_VIEW / PROP_SUBORDINATE_LIST. This issue has been patched in versions 1.4.4 and 1.5.1.

BACnet Stack: Out-of-Bounds Read in AtomicWriteFile Record Decoder via Unbounded returnedRecordCount

BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to versions 1.4.4 and 1.5.1, an out-of-bounds read vulnerability exists in bacnet-stack's AtomicWriteFile record-access path. The bug is caused by a mismatch between an externally controlled returnedRecordCount field and the fixed-size internal fileData[] array used by BACNET_ATOMIC_WRITE_FILE_DATA. This issue has been patched in versions 1.4.4 and 1.5.1.

BACnet Stack: Uninitialized Value Use in AtomicReadFile-ACK Record-Access Encoder Causes Response Corruption and Conditional Information Disclosure

BACnet Stack is a BACnet open source protocol stack C library for embedded systems. From versions 1.4.0 to before 1.4.4, and 1.5.0 to before 1.5.1, an uninitialized value use vulnerability in bacnet-stack's AtomicReadFile record-access ACK encoder allows unauthenticated remote attackers to corrupt the encoded OCTET STRING length and payload boundary in network responses by sending a crafted AtomicReadFile request that reaches a successful record-access path. This issue has been patched in versions 1.4.4 and 1.5.1.

BACnet Stack: Client-Side Out-of-Bounds Read in AtomicReadFile-ACK Record-Access Handling via RecordCount / fileData[] Mismatch

BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to versions 1.4.4 and 1.5.1, there is a client-side out-of-bounds read in the AtomicReadFile-ACK record-access handling path. The issue is caused by a mismatch between a remote returnedRecordCount value and the fixed local fileData[] array capacity in BACNET_ATOMIC_READ_FILE_DATA. The ACK decode path preserves the remote RecordCount, discards storage for excess records without truncating that count, and a downstream sink later iterates over the original RecordCount and indexes fileData[i] out of bounds. This issue has been patched in versions 1.4.4 and 1.5.1.

BACnet Stack: Channel member self-reference causes uncontrolled recursion and stack overflow in default BACnet/IP server

BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to versions 1.4.4 and 1.5.1, a remote attacker can trigger an uncontrolled recursion and stack overflow in the default server application of bacnet-stack by abusing the Channel object. This issue has been patched in versions 1.4.4 and 1.5.1.

BACnet Stack: ReinitializeDevice ENDRESTORE can delete existing objects on an empty restore file and still return success

BACnet Stack is a BACnet open source protocol stack C library for embedded systems. In versions 1.5.0 and 1.6.0-rc1, there is a restore logic flaw in bacnet-stack that is reachable through the official, unmodified apps/server management path when BACNET_BACKUP_RESTORE is enabled. This issue has been patched in versions 1.5.1 and 1.6.0.

BACnet Stack: Stack-based buffer overflow in Notification Class AddListElement recipient-list decoding

BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to versions 1.4.4, 1.5.1, and 1.6.0, a stack-based out-of-bounds write exists in the Notification Class object implementation when handling AddListElement for the recipient-list property. This issue has been patched in versions 1.4.4, 1.5.1, and 1.6.0.

BACnet Stack: Loop reference to long Structured View description causes stack-buffer-overflow

BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to versions 1.4.4, 1.5.1, and 1.6.0, a stack-buffer-overflow can be triggered in the current master branch when a Loop object reads a referenced property through its default timer path and the referenced property is OBJECT_STRUCTURED_VIEW / PROP_DESCRIPTION containing a long attacker-controlled string. This issue has been patched in versions 1.4.4, 1.5.1, and 1.6.0.

bacnet_stack 1.3.1 contains an Out-of-bounds Read in bacnet_tag_number_decode which allows attackers to cause a denial of service.

BACnet Stack: Out-of-Bounds Read in WritePropertyMultiple Decoder via Deprecated Tag Parser

BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to 1.4.3, an out-of-bounds read vulnerability in bacnet-stack's WritePropertyMultiple service decoder allows unauthenticated remote attackers to read past allocated buffer boundaries by sending a truncated WPM request. The vulnerability stems from wpm_decode_object_property() calling the deprecated decode_tag_number_and_value() function, which performs no bounds checking on the input buffer. A crafted BACnet/IP packet with a truncated property payload causes the decoder to read 1-7 bytes past the end of the buffer, leading to crashes or information disclosure on embedded BACnet devices. This vulnerability is fixed in 1.4.3.

BACnet Stack: Off-by-One Out-of-Bounds Read in ReadPropertyMultiple Object ID Decoder

BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to 1.4.3, an off-by-one out-of-bounds read vulnerability in bacnet-stack's ReadPropertyMultiple service decoder allows unauthenticated remote attackers to read one byte past an allocated buffer boundary by sending a crafted RPM request with a truncated object identifier. The vulnerability is in rpm_decode_object_id(), which checks apdu_len < 5 but then accesses all 6 byte positions (indices 0-5) — consuming 1 byte for the context tag, 4 bytes for the object ID, then reading apdu[5] for the opening tag check. A 5-byte input passes the length check but causes a 1-byte OOB read, leading to crashes on embedded BACnet devices. The vulnerability exists in src/bacnet/rpm.c and affects any deployment that enables the ReadPropertyMultiple confirmed service handler (enabled by default in the reference server). This vulnerability is fixed in 1.4.3.

BACnet Stack: Out-of-Bounds Read in ReadPropertyMultiple Property Decoder via Deprecated Tag Parser

BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to 1.4.3, an out-of-bounds read vulnerability in bacnet-stack's ReadPropertyMultiple service property decoder allows unauthenticated remote attackers to read past allocated buffer boundaries by sending an RPM request with a truncated property list. The vulnerability stems from rpm_decode_object_property() calling the deprecated decode_tag_number_and_value() function at src/bacnet/rpm.c:344, which accepts no buffer length parameter and reads blindly from whatever pointer it receives. A crafted BACnet/IP packet with a 1-byte property payload containing an extended tag marker (0xF9) causes the decoder to read 1 byte past the end of the buffer, leading to crashes on embedded BACnet devices. The vulnerability exists in src/bacnet/rpm.c and affects any deployment that enables the ReadPropertyMultiple confirmed service handler (enabled by default in the reference server). This vulnerability is fixed in 1.4.3.

BACnet Stack: Undefined-behavior signed left shift in `decode_signed32()`

BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to 1.4.3, decode_signed32() in src/bacnet/bacint.c reconstructs a 32-bit signed integer from four APDU bytes using signed left shifts. When any of the four bytes has bit 7 set (value ≥ 0x80), the left-shift operation overflows a signed int32_t, which is undefined behavior per the C standard. This is flagged thousands of times per minute by UndefinedBehaviorSanitizer on any BACnet input containing signed-integer property values with high-bit-set bytes. This vulnerability is fixed in 1.4.3.

The BACnet Protocol Stack library has an Off-by-one Stack-based Buffer Overflow in tokenizer_string

BACnet Protocol Stack library provides a BACnet application layer, network layer and media access (MAC) layer communications services. In 1.4.2, 1.5.0.rc2, and earlier, an off-by-one stack-based buffer overflow in the ubasic interpreter causes a crash (SIGABRT) when processing string literals longer than the buffer limit. The tokenizer_string function in src/bacnet/basic/program/ubasic/tokenizer.c incorrectly handles null termination for maximum-length strings. It writes a null byte to dest[40] when the buffer size is only 40 (indices 0-39), triggering a stack overflow.

BACnet Stack Improperly Limits Pathnames to a Restricted Directory

BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to 1.5.0.rc3, a vulnerability has been discovered in BACnet Stack's file writing functionality where there is no validation of user-provided file paths, allowing attackers to write files to arbitrary directories. This affects apps/readfile/main.c and ports/posix/bacfile-posix.c. This vulnerability is fixed in 1.5.0.rc3.

BACnet Stack WriteProperty decoding length underflow leads to OOB read and crash

BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to 1.5.0rc4 and 1.4.3rc2, a malformed WriteProperty request can trigger a length underflow in the BACnet stack, leading to an out‑of‑bounds read and a crash (DoS). The issue is in wp.c within wp_decode_service_request. When decoding the optional priority context tag, the code passes apdu_len - apdu_size to bacnet_unsigned_context_decode without validating that apdu_size <= apdu_len. If a truncated APDU reaches this path, apdu_len - apdu_size underflows, resulting in a large size being used for decoding and an out‑of‑bounds read. This vulnerability is fixed in 1.5.0rc4 and 1.4.3rc2.