[Dovecot-news] CVE-2020-25275: MIME parsing crashes with particular messages
Open-Xchange Security Advisory 2021-01-04 Product: Dovecot Vendor: OX Software GmbH Internal reference: DOV-4113 (Bug ID) Vulnerability type: CWE-20: Improper Input Validation Vulnerable version: 2.3.11-2.3.11.3 Vulnerable component: lda, lmtp, imap Report confidence: Confirmed Solution status: Fixed by Vendor Fixed version: 2.3.13 Vendor notification: 2020-09-10 Solution date: 2020-09-14 Public disclosure: 2021-01-04 CVE reference: CVE-2020-25275 CVSS: 5.3 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L) Researcher credit: Innokentii Sennovskiy (Rumata888) from BI.ZONE Vulnerability Details: Mail delivery / parsing crashed when the 10 000th MIME part was message/rfc822 (or if parent was multipart/digest). This happened due to earlier MIME parsing changes for CVE-2020-12100. Risk: Malicious sender can crash dovecot repeatedly by sending / uploading message with more than 10 000 MIME parts. Workaround: These are usually dropped by MTA, where the mitigation can also be applied. Solution: Operators should update to 2.3.13 or later version. signature.asc Description: OpenPGP digital signature ___ Dovecot-news mailing list Dovecot-news@dovecot.org https://dovecot.org/mailman/listinfo/dovecot-news
[Dovecot-news] CVE-2020-24386: IMAP hibernation allows accessing other peoples mail
Open-Xchange Security Advisory 2021-01-04 Product: Dovecot Vendor: OX Software GmbH Internal reference: DOP-2009 (Bug ID) Vulnerability type: CWE-150: Improper Neutralization of Escape, Meta, or Control Sequences Vulnerable version: 2.2.26-2.3.11.3 Vulnerable component: imap Report confidence: Confirmed Solution status: Fixed by Vendor Fixed version: 2.3.13 Vendor notification: 2020-08-17 Solution date: 2020-08-27 Public disclosure: 2021-01-04 CVE reference: CVE-2020-24386 CVSS: 8.2 (CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N) Vulnerability Details: When imap hibernation is active, an attacker can cause Dovecot to discover file system directory structure and access other users' emails using specially crafted command. The attacker must have valid credentials to access the mail server. Risk: Attacker can access other users' emails and filesystem information. Workaround: Operators can choose to disable IMAP hibernation. IMAP hibernation is not on by default. To ensure imap hibernation is disabled, make sure imap_hibernate_timeout is set to 0 or unset. Solution: Operators should update to 2.3.13 or later version. signature.asc Description: OpenPGP digital signature ___ Dovecot-news mailing list Dovecot-news@dovecot.org https://dovecot.org/mailman/listinfo/dovecot-news
[Dovecot-news] Pigeonhole v0.5.13 released
We are pleased to release pigeonhole 0.5.13. You can download it from
locations below:
https://pigeonhole.dovecot.org/releases/2.3/dovecot-2.3-pigeonhole-0.5.13.tar.gz
https://pigeonhole.dovecot.org/releases/2.3/dovecot-2.3-pigeonhole-0.5.13.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
---
- duplicate: The test was handled badly in a multiscript (sieve_before,
sieve_after) scenario in which an earlier script in the sequence with
a duplicate test succeeded, while a later script caused a runtime
failure. In that case, the message is recorded for duplicate tracking,
while the message may not actually have been delivered in the end.
- editheader: Sieve interpreter entered infinite loop at startup when
the "editheader" configuration listed an invalid header name. This
problem can only be triggered by the administrator.
- relational: The Sieve relational extension can cause a segfault at
compile time. This is triggered by invalid script syntax. The segfault
happens when this match type is the last argument of the test command.
This situation is not possible in a valid script; positional arguments
are normally present after that, which would prevent the segfault.
- sieve: For some Sieve commands the provided mailbox name is not
properly checked for UTF-8 validity, which can cause assert crashes at
runtime when an invalid mailbox name is encountered. This can be
caused by the user by writing a bad Sieve script involving the
affected commands ("mailboxexists", "specialuse_exists").
This can be triggered by the remote sender only when the user has
written a Sieve script that passes message content to one of the
affected commands.
- sieve: Large sequences of 8-bit octets passed to certain Sieve
commands that create or modify message headers that allow UTF-8 text
(vacation, notify and addheader) can cause the delivery or IMAP
process (when IMAPSieve is used) to enter a memory-consuming
semi-infinite loop that ends when the process exceeds its memory
limits. Logged in users can cause these hangs only for their own
processes.
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[Dovecot-news] Dovecot v2.3.13 released
We are pleased to release v2.3.13. Please find it from locations below:
https://dovecot.org/releases/2.3/dovecot-2.3.13.tar.gz
https://dovecot.org/releases/2.3/dovecot-2.3.13.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-2020-24386: Specially crafted command can cause IMAP hibernate to
allow logged in user to access other people's emails and filesystem
information.
* Metric filter and global event filter variable syntax changed to a
SQL-like format. See
https://doc.dovecot.org/configuration_manual/event_filter/
* auth: Added new aliases for %{variables}. Usage of the old ones is
possible, but discouraged.
* auth: Removed RPA auth mechanism, SKEY auth mechanism, NTLM auth
mechanism and related password schemes.
* auth: Removed passdb-sia, passdb-vpopmail and userdb-vpopmail.
* auth: Removed postfix postmap socket
+ auth: Added new fields for auth server events. These fields are now
also available for all auth events. See
https://doc.dovecot.org/admin_manual/list_of_events/#authentication-server
for details.
+ imap-hibernate: Added imap_client_hibernated, imap_client_unhibernated
and imap_client_unhibernate_retried events. See
https://doc.dovecot.org/admin_manual/list_of_events/ for details.
+ lib-index: Added new mail_index_recreated event. See
https://doc.dovecot.org/admin_manual/list_of_events/#mail-index-recreated
+ lib-sql: Support TLS options for cassandra driver. This requires
cpp-driver v2.15 (or later) to work reliably.
+ lib-storage: Missing $HasAttachment / $HasNoAttachment flags are now
added to existing mails if mail_attachment_detection_option=add-flags
and it can be done inexpensively.
+ login proxy: Added login_proxy_max_reconnects setting (default 3) to
control how many reconnections are attempted.
+ login proxy: imap/pop3/submission/managesieve proxying now supports
reconnection retrying on more than just connect() failure. Any error
except a non-temporary authentication failure will result in reconnect
attempts.
- auth: Lua passdb/userdb leaks stack elements per call, eventually
causing the stack to become too deep and crashing the auth or
auth-worker process.
- auth: SASL authentication PLAIN mechanism could be used to trigger
read buffer overflow. However, this doesn't seem to be exploitable in
any way.
- auth: v2.3.11 regression: GSSAPI authentication fails because dovecot
disallows NUL bytes for it.
- dict: Process used too much CPU when iterating keys, because each key
used a separate write() syscall.
- doveadm-server: Crash could occur if logging was done outside command
handling. For example http-client could have done debug logging
afterwards, resulting in either segfault or
Panic: file http-client.c: line 642 (http_client_context_close):
assertion failed: (cctx->clients_list == NULL).
- doveadm-server: v2.3.11 regression: Trying to connect to doveadm server
process via starttls assert-crashed if there were no ssl=yes listeners:
Panic: file master-service-ssl.c: line 22 (master_service_ssl_init):
assertion failed: (service->ssl_ctx_initialized).
- fts-solr: HTTP requests may have assert-crashed:
Panic: file http-client-request.c: line 1232
(http_client_request_send_more):
assertion failed: (req->payload_input != NULL)
- imap: IMAP NOTIFY could crash with a segmentation fault due to a bad
configuration that causes errors. Sending the error responses to the
client can cause the segmentation fault. This can for example happen
when several namespaces use the same mail storage location.
- imap: IMAP NOTIFY used on a shared namespace that doesn't actually
exist (e.g. public namespace for a nonexistent user) can crash with a
panic:
Panic: Leaked view for index /tmp/home/asdf/mdbox/dovecot.list.index:
Opened in (null):0
- imap: IMAP session can crash with QRESYNC extension if many changes
are done before asking for expunged mails since last sync.
- imap: Process might hang indefinitely if client disconnects after
sending some long-running commands pipelined, for example FETCH+LOGOUT.
- lib-compress: Mitigate crashes when configuring a not compiled in
compression. Errors with compression configuration now distinguish
between not supported and unknown.
- lib-compression: Using xz/lzma compression in v2.3.11 could have
written truncated output in some situations. This would result in
"Broken pipe" read errors when trying to read it back.
- lib-compression: zstd compression could have crashed in some situations:
Panic: file ostream.c: line 287 (o_stream_sendv_int): assertion
failed: (!stream->blocking)
- lib-dict: dict client could have crashed in some rare situations when
iterating keys.
- lib-http: Fix several assert-crashes in HTTP client.
- lib-index: v2.3.11 regression: When mails were expunged at the same
time as lots of new content was being saved to the cache (e.g. cache
file was lost
