Race condition in GNU nano before 2.2.4, when run by root to edit a file that is not owned by root, allows local user-assisted attackers to change the ownership of arbitrary files via vectors related to the creation of backup files.
Exploitability
AV:LAC:HAu:NImpact
C:PI:PA:P3.7/AV:L/AC:H/Au:N/C:P/I:P/A:P