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Improper Authentication


Severity Medium
Score 5.8/10


Plesk 8.6.0, when short mail login names (SHORTNAMES) are enabled, allows remote attackers to bypass authentication and send spam e-mail via a message with (1) a base64-encoded username that begins with a valid shortname, or (2) a username that matches a valid password, as demonstrated using (a) SMTP and qmail, and (b) Courier IMAP and POP3.

  • NONE
  • NONE

CWE-287 - Improper Authentication

Improper (or broken) authentication attacks are widespread, and have accounted for many of the worst data breaches in recent years. Improper authentication attacks are a class of vulnerabilities where an attacker impersonates a legitimate user by exploiting weaknesses in either session management or credential management to gain access to the user’s account. This can result in disclosure of sensitive information, and can lead to system compromise, theft, identity theft, and fraud.


Advisory Timeline

  • Published