Improper input validation in SAP NetWeaver Internet Communication Manager (update provided in KRNL32NUC & KRNL32UC 7.21, 7.21EXT, 7.22, 7.22EXT KRNL64NUC & KRNL64UC 7.21, 7.21EXT, 7.22, 7.22EXT, 7.49 KERNEL 7.21, 7.49, 7.53) allows an attacker to prevent users from accessing its services through a denial of service.