Dear subscribers,
we are sending notifications for three vulnerabilities,
- CVE-2020-10957
- CVE-2020-10958
- CVE-2020-10967
Please find them below
---
Aki Tuomi
Open-Xchange Oy
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Open-Xchange Security Advisory 2020-05-18
Product: Dovecot
Vendor: OX Software GmbH
Internal reference: DOV-3784
Vulnerability type: NULL pointer dereference (CWE-476)
Vulnerable version: 2.3.0 - 2.3.10
Vulnerable component: submission, lmtp
Report confidence: Confirmed
Solution status: Fixed by Vendor
Fixed version: 2.3.10.1
Researcher credits: Philippe Antoine (Catena Cyber)
Vendor notification: 2020-03-24
Solution date: 2020-04-02
Public disclosure: 2020-05-18
CVE reference: CVE-2020-10957
CVSS: 7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
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.
Solution:
Upgrade to fixed version.
------------------
Open-Xchange Security Advisory 2020-05-18
Product: Dovecot IMAP server
Vendor: OX Software GmbH
Internal reference: DOV-3875
Vulnerability type: Improper handling of input data (CWE-20)
Vulnerable version: 2.3.0 - 2.3.10
Vulnerable component: submission, lmtp
Report confidence: Confirmed
Solution status: Fixed by Vendor
Fixed version: 2.3.10.1
Researcher credits: Philippe Antoine (Catena Cyber)
Vendor notification: 2020-03-23
Solution date: 2020-04-02
Public disclosure: 2020-05-18
CVE reference: CVE-2020-10958
CVSS: 5.3 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L)
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.
Solution:
Upgrade to fixed version.
------------------
Open-Xchange Security Advisory 2020-05-18
Product: Dovecot
Vendor: OX Software GmbH
Internal reference: DOV-1745
Vulnerability type: Improper input validation (CWE-20)
Vulnerable version: 2.3.0 - 2.3.10
Vulnerable component: submission, lmtp
Report confidence: Confirmed
Solution status: Fixed by Vendor
Fixed version: 2.3.10.1
Researcher credits: mailbox.org
Vendor notification: 2020-03-20
Solution date: 2020-04-02
Public disclosure: 2020-05-18
CVE reference: CVE-2020-10967
CVSS: 5.3 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L)
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.
Solution:
Upgrade to fixed version.
------------------
We are pleased to release v2.3.10.1 Please find it from locations below:
https://dovecot.org/releases/2.3/dovecot-2.3.10.1.tar.gzhttps://dovecot.org/releases/2.3/dovecot-2.3.10.1.tar.gz.sig
Binary packages in https://repo.dovecot.org/
Docker images in https://hub.docker.com/r/dovecot/dovecot
Aki Tuomi
Open-Xchange oy
---
- CVE-2020-10957: lmtp/submission: A client can crash the server by
sending a NOOP command with an invalid string parameter. This occurs
particularly for a parameter that doesn't start with a double quote.
This applies to all SMTP services, including submission-login, which
makes it possible to crash the submission service without
authentication.
- CVE-2020-10958: lmtp/submission: Sending many invalid or unknown
commands can cause the server to access freed memory, which can lead
to a server crash. This happens when the server closes the connection
with a "421 Too many invalid commands" error. The bad command limit
depends on the service (lmtp or submission) and varies between 10 to
20 bad commands.
- CVE-2020-10967: lmtp/submission: Issuing the RCPT command with an
address that has the empty quoted string as local-part causes the
lmtp service to crash.