[[!comment format=mdwn
 username="joey"
 subject="""comment 1"""
 date="2020-05-08T16:50:14Z"
 content="""
This is due to the filename being passed through sanitizeFilePath.

There are security concerns here. If the filename contains "../"
it absolutely has to be modified, or the command would have to fail and
refuse the import it.

If the filename contains an ANSI escape sequence, it could potentially
lead to a security hole. Or if the filename starts with "-" it could be
somewhere between a possible security hole and just very annoying to work
with. As could a filename that contains a newline, which will
break large quantities of shell pipelines. While generally git repos can
have these problems with files in them too, the exposure seems larger when
talking to some random web server than when pulling from a repo.

Also, cross filesystem compatibility is a concern. It used to allow "|" in
the filename, but a bug pointed out that cannot be used on fat filesystems.
And "\\" means different things on linux and windows, so probably best to avoid
filenames containing it on linux too.

Finally, it's somewhat opinionated, since it replaces spaces with
underscores. That's certainly the least defensible thing.

(git-annex may also truncate the filename if it's longer than what the
filesystem supports.)

So, it's clearly wrong that it should be taken as-is without obfuscation,
IMHO. Maybe there's a way to improve it to meet some use case though.

I could see having a config that avoids sanitizing the filename, but
makes addurl fail if the filename looks like a security problem. 

Though that has the downside that git-annex would then need to
comprehensively track, going forward, all the ways that people find to make
filenames be a security problem; the current method, by being strict in
what it lets through, probably limits expoits to ones involving a) unicode
or b) the user's wetware.
"""]]
