The GridFTP in Globus Toolkit (GT) before 5.2.2, when certain autoconf macros are defined, does not properly check the return value from the getpwnam_r function, which might allow remote attackers to gain privileges by logging in with a user that does not exist, which causes GridFTP to run as the last user in the password file.

The GridFTP in Globus Toolkit (GT) before 5.2.2, when certain autoconf macros are defined, does not properly check the return value from the getpwnam_r function, which might allow remote attackers to gain privileges by logging in with a user that does not exist, which causes GridFTP to run as the last user in the password file.