[horde] Is quoted-printable a problem

[Michael M Slusarz]

Quoting Gary <witscher at gmail.com>:

> Quoting Simon B <simon.buongiorno at gmail.com>:
>
>> On 27 Jul 2015 15:12, "Michael M Slusarz" <slusarz at horde.org> wrote:
>>>
>>> Quoting Gary <witscher at gmail.com>:
>>>
>>>> Hello,
>>>>
>>>> Running Arch Linux on a Lenovo T430 using Firefox.
>>>>
>>>> I get an email periodically from my bank that won't display in imp. I
>> can read it find in gmail or any desktop client I try. If I use imp to open
>> the message source the only thing that caches my eye is this:
>>>>
>>>> Content-Type: text/html; charset=us-ascii
>>>> Content-Transfer-Encoding: quoted-printable
>>>>
>>>> The actual text of the message is readable when viewed in source (it's
>> an html message). However every line ends in an "=" sign and all lines are
>> perfectly aligned. Almost looks like it's encoded, but the characters are
>> all plain text. When I view the message in imp's normal message view it's
>> just a block of non-text characters:
>>>>
>>>>
>> ℼ佄呃偙⁅瑨汭倠䉕䥌⁃ⴢ⼯㍗⽃䐯䑔䠠䵔⁌⸴‰牔湡楳楴湯污⼯久•栢瑴㩰⼯睷⹷㍷漮杲启⽒䕒ⵃ瑨汭〴氯潯敳搮摴㸢㰊砿汭攠据摯湩㵧唢䙔㠭㼢㰾瑨汭㰾敨摡㰾敭慴栠瑴⵰煥極㵶挢湯整瑮琭灹≥挠湯整瑮∽整瑸栯浴㭬挠慨獲瑥唽䙔㠭㸢洼瑥⁡瑨灴攭畱癩∽⵸湤⵳牰晥瑥档挭湯牴汯•
>>>>
>>>> I can't find any settings that affect this issue. This is the only
>> message source that causes this problem. Anyone have an idea how I can fix
>> this?
>>>
>>>
>>> That text is *NOT* us-ascii.  Sounds like that message is completely
>> broken.
>>
>> I've seen this before.  I don't remember exactly, but the text is double
>> encoded.  I.e. it's ascii being reported as UTF-8 and then being "encoded"
>> to ascii again.
>>
>> Simon
>> --
>
> An interesting idea. Is this sort of thing common enough that other  
> email clients understand this format and are able to process it? It  
> displays perfectly in Sylpheed, Gmail, and android AquaMail.

Horde/IMP handles correctly formatted quoted-printable just fine.  Has  
for about 17 years now.

You haven't provided the actual message source of the problem message,  
so there's not much we can do besides speculate at this point.

I will note that if other mail user agents are "correctly" displaying  
messages that are demonstrably broken or malformed, that is a security  
risk -- or at least a giant hole that makes SPAM detection completely  
worthless on those installations.

michael

___________________________________
Michael Slusarz [slusarz at horde.org]