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             AUSCERT External Security Bulletin Redistribution

                    Dovecot -- Multiple vulnerabilities
                                19 May 2020


        AusCERT Security Bulletin Summary

Product:           dovecot
Publisher:         FreeBSD
Operating System:  FreeBSD
Impact/Access:     Execute Arbitrary Code/Commands -- Remote with User Interaction
                   Denial of Service               -- Remote/Unauthenticated      
Resolution:        Patch/Upgrade
CVE Names:         CVE-2020-10967 CVE-2020-10958 CVE-2020-10957

Reference:         ESB-2020.1762

Original Bulletin: 

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Dovecot -- Multiple vulnerabilities

Affected packages
  dovecot <


VuXML ID  37d106a8-15a4-483e-8247-fcb68b16eaf8
Discovery 2020-04-02
Entry     2020-05-18

Aki Tuomi reports:

    Vulnerability Details: Sending malformed NOOP command causes crash in
    submission, submission-login or lmtp service. Risk: Remote attacker can
    keep submission-login service down, causing denial of service attack. For
    lmtp the risk is neglible, as lmtp is usually behind a trusted MTA. Steps
    to reproduce: Send ``NOOP EE"FY`` to submission port, or similarly
    malformed command.

    Vulnerability Details: Sending command followed by sufficient number of
    newlines triggers a use-after-free bug that might crash submission-login,
    submission or lmtp service. Risk: Remote attacker can keep submission-login
    service down, causing denial of service attack. For lmtp the risk is
    neglible, as lmtp is usually behind a trusted MTA. Steps to reproduce: This
    can be currently reproduced with ASAN or Valgrind. Reliable way to crash
    has not yet been discovered.

    Vulnerability Details: Sending mail with empty quoted localpart causes
    submission or lmtp component to crash. Risk: Malicious actor can cause
    denial of service to mail delivery by repeatedly sending mails with bad
    sender or recipient address. Steps to reproduce: Send mail with envelope
    sender or recipient as <""@example.org>. Workaround: For submission there
    is no workaround, but triggering the bug requires valid credentials. For
    lmtp, one can implement sufficient filtering on MTA level to prevent mails
    with such addresses from ending up in LMTP delivery.



CVE Name CVE-2020-10957
CVE Name CVE-2020-10958
CVE Name CVE-2020-10967
URL      https://dovecot.org/pipermail/dovecot-news/2020-May/000438.html

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