All sensors, whether interior or exterior, are vulnerable to attack. Some precautions will help reduce their vulnerability:
Tamper-protection methods generate a “tamper” alarm if an attacker attempts to defeat the sensor. Because signal-processing circuitry for exterior sensors is generally more vulnerable to tampering and defeat than the circuitry for interior sensors, enclosures must be located and installed properly. Adequate physical protection must be provided.
https://www.fs.usda.gov/t-d/phys_sec/alarms/vulner.htm