Stack-based buffer overflow in the normify function in the rlm_pap module (modules/rlm_pap/rlm_pap.c) in FreeRADIUS 2.x, possibly 2.2.3 and earlier, and 3.x, possibly 3.0.1 and earlier, might allow attackers to cause a denial of service (crash) and possibly execute arbitrary code via a long password hash, as demonstrated by an SSHA hash.