Deprecation of the MAIL-FROM auth scheme
Dear Colleagues, Another issues that was discussed at the RIPE-41 meeting is deprecation of a MAIL-FROM authentication scheme. It was agreed that the weakness of this auth form does not allow to provide real protection to the database objects and it should be deprecated. As a matter of fact recently we had to deal with several incidents when objects were hijacked using the flaw of the MAIL-FROM. It took time and resources from the ripe-dbm to investigate the matter and restore the objects, to say nothing about possible damage to the owners of such objects should the incident has gone unnoticed. Please find enclosed the migration plan to a more secure database. Your comments are welcome. Regards, Andrei Robachevsky DB Group Manager RIPE NCC Deprecation of MAIL-FROM authentication and authorisation scheme (auth scheme) ============================================================================== Motivation ========== This authentication method checks the content of the RFC2822 From: header of an update request against the regular expression specified as <auth-info> field of the "auth:" attribute. If the regular expression matches the content of the From: header the update request is authenticated successfully. The matching is applied to the whole content of the From: header including comments if present. No attempt is made to isolate the mailbox part. This authentication scheme is very weak. Forging RFC2822 headers can be done very easily. With the existence of more secure "auth" schemes in the RIPE Database, it does not make much sense to support it any more. Currently 41% (~2700) of all mntner objects in the RIPE Database are using this weak "auth" scheme. Though NONE "auth" scheme is even weaker it is not supposed to be consciously used for object protection, but rather as notification facility. Therefore NONE "auth" scheme is outside the scope of this proposal. Transition phases ================== I Notifying mntners with MAIL-FROM auth scheme ----------------------------------------------- An announcement presenting this proposal and encouraging the owners of the mntners to remove MAIL-FROM auth scheme from their objects will be send. The distribution list will be compiled from e-mail addresses listed in "upd-to:", "mnt-nfy:" attributes of the mntners, as well as using contact information (e-mail) from "admin-c:" and "tech-c:" references. II Rejecting updates for mntner objects containing MAIL-FROM auth scheme ------------------------------------------------------------------------- An update of a mntner object will be rejected if the new version of the mntner contains MAIL-FROM auth scheme. This will be reported as a syntax error in the "auth:" attribute. III Rejecting using the MAIL-FROM auth scheme for authorisation --------------------------------------------------------------- When processing an update for an object protected by a mntner that contains MAIL-FROM auth scheme, this scheme will be ignored. That means that if mntner defines other auth schemes different from MAIL-FROM, the credentials relevant to these schemes may be used. If the only auth scheme defined is MAIL-FROM, no update can be authorised by such mntner. In case of failure the acknowledgement will indicate that MAIL-FROM "auth" scheme is not valid any more. IV Cleanup ---------- The mntners still containing "auth:" attribute with the MAIL-FROM auth scheme will be modified so that such attributes will be removed from the objects. Before this a final call will be sent to the owners of these mntners ("upd-to:", "mnt-nfy:" attributes of the mntners, as well as to the contacts from "admin-c:" and "tech-c:" references). A "remarks:" attrubute will be added with clear explanation of the situation. In case a mntner contains only one "auth" scheme, which is MAIL-FROM, it will be replaced with a CRYPT-PW scheme with a DES string that cannot be matched.
Dear Andrei & list, talking about a secure database, I wonder why the crypted password is shown when using CRYPT-PW as authentication scheme? While it might take long to get the clear-text password using brute force or dictionary attacks, it is still possible. Why not patch the whois server so it doesn't show the crypted password and hence make hijacking of objects impossible by bruteforcing a maintainer password? Best regards Christoph Kuhles Managing Director Aquatix IT-Services e.K. Monday, March 25, 2002, 1:58:10 PM, you wrote: AR> Please find enclosed the migration plan to a more secure database.
participants (2)
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Andrei Robachevsky
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Christoph Kuhles / Aquatix RIPE services