OpenSSL before 0.9.8m does not check for a NULL return value from bn_wexpand function calls in (1) crypto/bn/bn_div.c, (2) crypto/bn/bn_gf2m.c, (3) crypto/ec/ec2_smpl.c, and (4) engines/e_ubsec.c, which has unspecified impact and context-dependent attack vectors.