Friessner enlisted in the German Army in 1911 and, after seeing extensive duty during World War I, served in the Reichswehr following the war.

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. Shortly after his promotion to Generalleutnant on 1 October 1942, Friessner served as commander of the XXIII Corps from 19 January to 11 December 1943. On 1 April 1943, he was promoted General der Infanterie (General of the Infantry).

In February 1944, Friessner was transferred to the Northern Front and assigned command to Sponheimer Group (renamed army detachment "Narva" on 23 February). Promoted to Generaloberst on 1 July, Friessner briefly held command of Army Group North until 25 July before being sent to the southern front to command Army Group South Ukraine (later redesignated Army Group South). 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. Holding no further command for the remainder of the war, Friessner lived in retirement in Bayerisch Gmain until his death on 26 June 1971.