[exim] Plain authentication with pam: Password problem

Hello,

we have configured a plain authenticator with PAM:

plain:
     driver = plaintext
     public_name = PLAIN
     server_prompts = :
     # seehttp://exim.org/exim-html-current/doc/html/spec_html/ch-string_expansions.html  - pam{...
     server_condition = ${if pam{$auth2:${sg{$auth3}{:}{::}}}{yes}{no}}
     server_set_id = $auth2

A user "tester" with a password starting with a colon can't authenticate:

pam_krb5[10327]: authentication fails for 'tester:' ...
                                               ---^

Is there a workaround for users with :passwords?

Kind regards,
Frank

--
Frank Richter
Chemnitz University of Technology, Germany