TinyOS versions up to 2.1.2 contain a global buffer overflow in the printfUART implementation used by the ZigBee / IEEE 802.15.4 stack. The function writes formatted output into a fixed‑size global buffer and concatenates %s strings with strcat() without checking remaining capacity. When called with a longer user‑controlled string, the unbounded write corrupts global memory, which can lead to denial of service, unintended behavior, or information disclosure through corrupted adjacent state or UART output.

All installations of TinyOS 2.1.2 and earlier are vulnerable. No newer versions are affected.

The CVSS score of 5.1 indicates moderate severity. The EPSS score is below 1 %, suggesting a low probability of widespread exploitation. The vulnerability is not listed in the CISA KEV catalog. Based on the description, it is inferred that an attacker would need to control the string passed to printfUART, and the likely attack vector is via the UART debugging interface where the vulnerable function is invoked. If successfully triggered, the attacker can cause the device to crash or leak sensitive data.