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author | Sergio <shernade@gmail.com> | 2013-09-15 23:51:31 +0200 |
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committer | Sergio <shernade@gmail.com> | 2013-09-15 23:51:31 +0200 |
commit | ebcd9d6c03fecc6946c794c19c544b5f1349b8f1 (patch) | |
tree | c23ccbf17becb5a7192fa5d7b6cdb350910fde5c | |
parent | b827663e5f6646eb6aaceac1f04a09db993ec5bf (diff) | |
download | rails-ebcd9d6c03fecc6946c794c19c544b5f1349b8f1.tar.gz rails-ebcd9d6c03fecc6946c794c19c544b5f1349b8f1.tar.bz2 rails-ebcd9d6c03fecc6946c794c19c544b5f1349b8f1.zip |
surplus : in attachment_fu plugin
surplus ':' character in url
-rw-r--r-- | guides/source/security.md | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/guides/source/security.md b/guides/source/security.md index 4aba39f55a..0c2d3caa4e 100644 --- a/guides/source/security.md +++ b/guides/source/security.md @@ -290,7 +290,7 @@ NOTE: _Make sure file uploads don't overwrite important files, and process media Many web applications allow users to upload files. _File names, which the user may choose (partly), should always be filtered_ as an attacker could use a malicious file name to overwrite any file on the server. If you store file uploads at /var/www/uploads, and the user enters a file name like "../../../etc/passwd", it may overwrite an important file. Of course, the Ruby interpreter would need the appropriate permissions to do so - one more reason to run web servers, database servers and other programs as a less privileged Unix user. -When filtering user input file names, _don't try to remove malicious parts_. Think of a situation where the web application removes all "../" in a file name and an attacker uses a string such as "....//" - the result will be "../". It is best to use a whitelist approach, which _checks for the validity of a file name with a set of accepted characters_. This is opposed to a blacklist approach which attempts to remove not allowed characters. In case it isn't a valid file name, reject it (or replace not accepted characters), but don't remove them. Here is the file name sanitizer from the [attachment_fu plugin](https://github.com/technoweenie/attachment_fu/tree/master:) +When filtering user input file names, _don't try to remove malicious parts_. Think of a situation where the web application removes all "../" in a file name and an attacker uses a string such as "....//" - the result will be "../". It is best to use a whitelist approach, which _checks for the validity of a file name with a set of accepted characters_. This is opposed to a blacklist approach which attempts to remove not allowed characters. In case it isn't a valid file name, reject it (or replace not accepted characters), but don't remove them. Here is the file name sanitizer from the [attachment_fu plugin](https://github.com/technoweenie/attachment_fu/tree/master) ```ruby def sanitize_filename(filename) |