A Cross-site Scripting issue was discovered in PHOENIX CONTACT FL COMSERVER BASIC 232/422/485 FL COMSERVER UNI 232/422/485 FL COMSERVER BAS 232/422/485-T FL COMSERVER UNI 232/422/485-T FL COM SERVER RS232 FL COM SERVER RS485 and PSI-MODEM/ETH (running firmware versions prior to 1.99 2.20 or 2.40). The cross-site scripting vulnerability has been identified which may allow remote code execution.