Neohapsis is currently accepting applications for employment. For more information, please visit our website www.neohapsis.com or email email@example.com
Re: ConnecTalk Security Advisory: Qpopper leaks information during authentication
From: Justin Wheeler (jwheelerdatademons.com)
Date: Wed Jun 18 2003 - 15:09:15 CDT
This bug does not exist in QPopper 3.x, as it simply closes the connection
regardless of whether the username is valid or not.
Programmer - A red-eyed, mumbling mammal capable of conversing with inanimate objects.
On Wed, 18 Jun 2003, Marc Lafortune wrote:
> ConnecTalk Inc. Security Advisory
> Topic: Qpopper leaks information during authentication
> Vendor: Eudora
> Product: qpopper 4.0.4 and qpopper 4.0.5
> Note: other versions have not been tested.
> Problem found: May 14, 2003
> Vendor notification: May 14, 2003
> Second vendor notification: May 21, 2003
> Public notification: June 18, 2003
> I. Background
> Qpopper is the most widely-used server for the POP3 protocol (this
> allows users to access their mail using any POP3 client). Qpopper
> supports the latest standards, and includes a large number of optional
> features. Qpopper is normally used with standard UNIX mail transfer and
> delivery agents such as sendmail or smail.
> II. Problem Description
> When Qpopper is in the authentication phase, using plain text passwords,
> the response to the PASS command differs depending on the existance of
> the USER. If a valid username and a wrong password are given, Qpopper
> returns a negative reponse and waits for one more command before closing
> the connection. If an invalid username and password are given, Qpopper
> returns a negative response and disconnects right away.
> III. Impact
> A remote attacker can use this information leak to validate the
> existance of a user account.
> Marc Lafortune
> Intégrateur / Integrator
> ConnecTalk Inc.