Siemens Desigo PX Web modules PXA40-W0, PXA40-W1, PXA40-W2 for Desigo PX automation controllers PXC00-E.D, PXC50-E.D, PXC100-E.D, PXC200-E.D (All firmware versions < V6.00.046) and Desigo PX Web modules PXA30-W0, PXA30-W1, PXA30-W2 for Desigo PX automation controllers PXC00-U, PXC64-U, PXC128-U (All firmware versions < V6.00.046) use a pseudo random number generator with insufficient entropy to generate certificates for HTTPS, potentially allowing remote attackers to reconstruct the corresponding private key.