The default configuration of Slackware 3.4, and possibly other versions, includes . (dot, the current directory) in the PATH environmental variable, which could allow local users to create Trojan horse programs that are inadvertently executed by other users.
Win32 ICQ 98a 1.30, and possibly other versions, does not display the entire portion of long filenames, which could allow attackers to send an executable file with a long name that contains so many spaces that the .exe extension is not displayed, which could make the user believe that the file is safe to open from the client.
PIM software for Royal daVinci does not properly password-protext access to data stored in the .mdb (Microsoft Access) file, which allows local users to read the data without a password by directly accessing the files with a different application, such as Access.
A system is running a version of software that was replaced with a Trojan Horse at one of its distribution points, such as (1) TCP Wrappers 7.6, (2) util-linux 2.9g, (3) wuarchive ftpd (wuftpd) 2.2 and 2.1f, (4) IRC client (ircII) ircII 2.2.9, (5) OpenSSH 3.4p1, or (6) Sendmail 8.12.6.
The ugidd RPC interface, by design, allows remote attackers to enumerate valid usernames by specifying arbitrary UIDs that ugidd maps to local user and group names.
In Windows NT, an inappropriate user is a member of a group, e.g. Administrator, Backup Operators, Domain Admins, Domain Guests, Power Users, Print Operators, Replicators, System Operators, etc.
The default setting for the Winlogon key entry ShutdownWithoutLogon in Windows NT allows users with physical access to shut down a Windows NT system without logging in.