Note: You cannot put chpass directly into your web space, as chpass' setuid bit and root ownership may interfere with Apache's suexec facility.
#!/bin/sh exec /usr/local/bin/chpass.cgi "$@"
You may also put in any additional pam modules, such as pam_smbpass, in order to have all passwords (both Unix and Samba) changed at once. You get the full flexibility of PAM.
password required pam_warn.so password required pam_pwcheck.so use_cracklib password required pam_unix2.so use_first_pass