[1] After his promotion to Generalmajor during World War II on 1 August 1940, Frießner was assigned to the Eastern Front on 1 May 1942 and placed in command of the 102nd Infantry Division.

Unable to halt the four month Soviet offensive by Marshal Rodion Malinovsky's Second Ukrainian Front, Friessner was relieved of his command on 22 December.

In September 1951 he was elected the chairman of the Verband deutscher Soldaten [de] (Union of German Soldiers, VdS), however he resigned in December 1951.

Frießner was no longer tenable as chairman of the VdS after he had justified the invasion of Poland as a legitimate measure to "protect the ethnic Germans in Poland" at a press conference on 21 September 1951 and he had favourably compared the "decently fighting Waffen-SS" to the officers of the 20 July plot, who, according to him, had chosen a method that was to be rejected "from the military point of view", and namely "political murder".

In 1956, Frießner wrote Verratene Schlachten (Betrayed Battles), a memoir of his tour of command of Army Group South Ukraine.