Incomplete blacklist vulnerability in the chfn function in libuser before 0.56.13-8 and 0.60 before 0.60-7, as used in the userhelper program in the usermode package, allows local users to cause a denial of service (/etc/passwd corruption) via a newline character in the GECOS field.

libuser before 0.56.13-8 and 0.60 before 0.60-7, as used in the userhelper program in the usermode package, directly modifies /etc/passwd, which allows local users to cause a denial of service (inconsistent file state) by causing an error during the modification. NOTE: this issue can be combined with CVE-2015-3245 to gain privileges.