The LoRaWAN application-layer clock-synchronization service parses downlinks in clocksyncpackagecallback() (subsys/lorawan/services/clocksync.c). Its command loop only guarantees that the one-byte command id is in bounds; for the CLOCKSYNCCMDAPPTIME (AppTimeAns) command the handler then reads a 4-byte time correction via sysgetle32() plus a 1-byte token without checking that 5 bytes remain in the receive buffer (len - rxpos). A short or crafted AppTimeAns therefore reads up to 5 bytes past the end of the decrypted payload.

The payload (rxbuf/len) is the decrypted application frame delivered to the registered downlink callback (mcpsindication->Buffer/BufferSize). Reaching the handler requires a frame on the clock-sync port that passes LoRaWAN's MAC integrity check and FRMPayload decryption, so the practical attacker is a malicious or compromised network/application server (the designated sender of AppTimeAns) or a party holding the session keys, rather than an arbitrary radio listener.

The over-read is bounded: the backing store is a fixed 255-byte static buffer, so the few stray bytes do not fault, and the read values (timecorrection, token) are used only internally and never transmitted, so there is no disclosure to the attacker and no crash. The sole effect is that a stale token matching ctx.reqtoken can apply a garbage timecorrection to the device's own clock offset (ctx.timeoffset), a minor integrity impact confined to the victim's time estimate. The fix adds an explicit length check that drops a too-short AppTimeAns. Note the sibling one-byte reads in the periodicity and force-resync handlers remain unguarded with the same negligible impact.

The Zephyr Bluetooth controller ISO Adaptation Layer (subsys/bluetooth/controller/llsw/isoal.c) fails to validate the length field of a framed ISO PDU start segment. Per the Bluetooth specification a start segment (sc=0) always carries a 3-byte timeoffset, so its segment-header len must be at least PDUISOSEGTIMEOFFSETSIZE (3). isoalchecksegheader() accepted start segments with len < 3 as valid, and isoalrxframedconsume() then computed length = seghdr->len - 3 in a uint8t, underflowing to 253-255 when len is 0-2. That oversized length is passed to isoalrxappendtosdu(), whose copy is clamped only against the destination SDU buffer size, not the source PDU length, so up to ~255 bytes of controller memory beyond the received PDU are copied (via sinksduwritehci()/netbufaddmem) into an HCI ISO data packet and delivered to the host. The PDU and its segment headers are entirely attacker-controlled and arrive over the air, reachable through both the CIS and BIS-sync HCI data paths (hcidriver.c) and the vendor data path (ulliso.c), so a remote CIS peer or a broadcaster the device is synced to can trigger an out-of-bounds read causing information disclosure to the host and potential denial of service (faults or malformed oversized HCI ISO packets). The flaw affects all Zephyr releases since framed ISO reception was introduced in v3.0.0. The fix rejects sc=0 segments with len < 3 in isoalchecksegheader() and adds a guard before the subtraction in isoalrxframedconsume().

Zephyr's IPv6 Neighbor Discovery send paths (netipv6sendna, netipv6sendns, netipv6sendrs in subsys/net/ip/ipv6nbr.c) updated the per-interface ICMP-sent statistics by calling netpktiface(pkt) after netsenddata(pkt) had already returned successfully. On the success path the network stack owns and releases the packet's reference (the L2/driver send unrefs it, e.g. ethernetsend -> netpktunref), so for a freshly allocated packet with refcount 1 the netpkt slab block can be freed before the statistics line runs (synchronously when no TX queue thread is configured, or via a concurrent TX thread otherwise).

The subsequent netpktiface(pkt) reads pkt->iface from the freed slab block, and with CONFIGNETSTATISTICSPERINTERFACE enabled that loaded pointer is dereferenced to increment iface->stats.icmp.sent, a use-after-free (CWE-416). If the slab block was reallocated in the meantime the read/increment targets unrelated or attacker-influenced memory, yielding corrupted statistics, a fault/crash (denial of service), or potential limited memory corruption.

The vulnerable Neighbor Advertisement path is reachable by any unauthenticated on-link node simply by sending ICMPv6 Neighbor Solicitations to a Zephyr node with native IPv6 enabled (handlensinput -> netipv6sendna).

Affected from v3.3.0 through v4.4.0; the fix uses the already-available iface argument instead of touching the sent packet. Configurations without per-interface statistics dereference only a global counter and are not affected by the memory-safety aspect.