[ZBX-5454] Length of encoded subject violate RFC2047 : The subject part will be made "Mojibake" - failing MIME encode -, when the decoded subject length is over 75 bytes. Created: 2012 Aug 15  Updated: 2017 May 30  Resolved: 2012 Sep 07

Status: Closed
Component/s: Server (S)
Affects Version/s: None
Fix Version/s: 1.8.16rc1, 2.0.4rc1, 2.1.0

Type: Incident report Priority: Minor
Reporter: Haruyoshi CHIYODA Assignee: Unassigned
Resolution: Fixed Votes: 0
Labels: actions, usability

I discovered this problem in zabbix 1.8.3. However, I worry that in latest version have it yet.

Attachments: File zabbix-2.0.1-mail-rfc2074.patch    
Issue Links:
is duplicated by ZBX-5455 Length of encoded subject violate RFC... Closed


Please Length of encoded subject make shorter than 75 characters with Email notice.
I discovered this problem in zabbix 1.8.3. However, I worry that in latest version have it yet.

When you send message with the Email (media type), zabbix sending with MIME decoded Header like below...
But, in this case some user received the alert mail which have that "Subject" part is "Mojibake".

Subject: =?UTF-8?B?5pel5pys6Kqe44Gg44KI44CC44CO5LuK5pel44KC5YWD5rCX44Gr44G/44KT44Gq6aCR5by144KM44CCWmFiYml444GL44KJ44Ki44Op44O844OI5Ye644Gm44G+44GZ44CC44Ob44K544OI5ZCN44GvaG9zdG5hbWVob2dl44Gn44Ki44Kk44OG44Og44GvaXRlbWhvZ2XjgafnirbmhYvjga9Qcm9ibGVtOjEwMCXjgac=44GZ44KI44CC44CP?=
MIME-Version: 1.0
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: base64

This hedder is almost correct, but "Subject" is too long. "RFC2047" says as below...

An 'encoded-word' may not be more than 75 characters long, including 'charset', 'encoding', 'encoded-text', and delimiters.
If it is desirable to encode more text than will fit in an 'encoded-word' of 75 characters, multiple 'encoded-word's
(separated by CRLF SPACE) may be used. (Ref. http://www.ietf.org/rfc/rfc2047.txt )

I think the "Subject" part should be as bellow...

Subject: =?UTF-8?B?5pel5pys6Kqe44Gg44KI44CC44CO5LuK5pel44KC5YWD5rCX44Gr44G/44KT?=

For Example: The case of microsoft exchange 2007
By default, Exchange Server 2007 will not attempt to decode any subject header that exceeds
a total encoded length greater than 255 characters.
So the subject line will be garbled when the limit has been reached.
(Microsoft Exchange 2010(1000 Byte) is better than 2007(256 Byte) in Japanese Env.)

Comment by Kodai Terashima [ 2012 Aug 15 ]

I confirmed. Zabbix serve does not split mime encorded subject in 1.8 latest, and 2.0 has same code.

Comment by Jairo Eduardo Lopez Fuentes Nacarino [ 2012 Aug 28 ]


my name is Jairo Lopez, I have made a patch to solve the Mojibake issue and RFC2047 compliance for email subjects.

Attached is my first attempt at a patch.

I was working on a Zabbix 2.0.1 but the patch should be able to be applied with no major changes up to the 2.0.3rc1 version.

I thank for your time and hope to get feedback.

Comment by Andris Mednis [ 2012 Aug 28 ]

Thanks, Jairo, for your patch!
It will help to fix the issue faster.

Comment by Andris Mednis [ 2012 Sep 04 ]

Hi, Jairo!

I took your patch as a basis for fixing the issue. Currently working on fixing 1.8 and modifying the patch to our coding guidelines. Thanks for your contribution!

Comment by Jairo Eduardo Lopez Fuentes Nacarino [ 2012 Sep 05 ]

Hi Andris!

I am glad the patch was of use!

I realized that my code was not fully compliant with your coding guidelines a couple of days ago. For next time I'll be more careful so that you guys have more time to check the thought process.

Thank you for the feedback and for taking time to look at the issue. I am looking forward to seeing the end result!

Comment by Andris Mednis [ 2012 Sep 07 ]

Fixed in development branch svn://svn.zabbix.com/branches/dev/ZBX-5454 (for 1.8 branch)
Fixed in development branch svn://svn.zabbix.com/branches/dev/ZBX-5454-2.0 (for 2.0 branch)

Comment by Alexander Vladishev [ 2012 Sep 14 ]

Successfully tested!

Please review my changes in r30223 and r30224.

Comment by Andris Mednis [ 2012 Oct 05 ]

Fixed in versions pre-1.8.16 rev.30670, pre-2.0.4 rev. 30675 and pre-2.1.0 rev. 30676.

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