PScan is a C source code security scanner, which looks for misuse of
libc functions which use varargs and printf-style formatting
operators. In many situations these can cause security vulnerabilities
in the application if it runs with privileges (setugid, or listening
to a network socket, etc).

An example of the kind of situation pscan looks for is the following:

  variable = "%s";                   /* or malicious user input */
  sprintf(buffer, variable);         /* BAD! */

WWW: http://www.striker.ottawa.on.ca/~aland/pscan/