View Issue Details

IDProjectCategoryView StatusLast Update
14091Bug reportsSurvey takingpublic2021-03-11 11:38
Reportertbart Assigned To 
Status newResolutionreopened 
Product Version3.13.x 
Summary14091: Filenames of uploads starting with special characters truncated
DescriptionNon-ANSI characters (e.g. umlauts (äöü) ) at the beginning of uploaded files are cut off.
Steps To ReproduceWhen taking a survey that contains a file upload field:
1. Choose a file with an umlaut at the beginning
2. See file with umlaut at the beginning cut off
Additional InformationThis is due to locale-awareness of PHP's basename().
Also see for other related functions with the same feature.


setlocale(LC_ALL, 'en_US.UTF8');

in index.php fixes it, but I am sure this is not the right place to add this.

My system locale (on debian) is correctly set (apart from LC_ALL, which normally is just an override and should not be set).

Please either respect system's LANG or set the locale to some UTF-8 compatible one.
TagsNo tags attached.
Complete LimeSurvey version number (& build)3.14.9+180917
I will donate to the project if issue is resolvedNo
Database & DB-VersionmySQL 5.5.60
Server OS (if known)debian
Webserver software & version (if known)apache 2.4.10
PHP Version5.6.36




2019-01-10 17:40

developer   ~50169

yes we have hard filtering of file names for security reason.


2019-01-14 17:40

reporter   ~50188

I understand file names get filtered, but this does not seem related. Why does setting the correct locale circumvent the filtering?
I feel like filtering should be done after correctly interpreting the code points with the correct locale.

But I may be wrong.

If only ASCII (or even a more reduced subset) is allowed, a note should advise users to rename their files (and only list allowed characters). Though this seems pretty uncommon. There should be standard functions to sanitize the string and frankly, umlauts don't seem all too dangerous :)


2019-01-15 08:40

developer   ~50192

Last edited: 2019-01-15 08:51

View 2 revisions

«yes we have hard filtering of file names for security reason. » ???

Filtering äöü have nothing with security , andis not filtered like this in 'Upload question' type.

@tbart : where it's filtered like this ? And what is the broken locale



2019-01-15 08:40




2019-01-15 09:06

reporter   ~50194

Your filenames do not start with special characters. See screenshot attached.

The locale should be en_US.UTF-8, at least that's what the environment sets for LANG:

# set | egrep "^(LANG|LC)"


2019-01-15 10:00

developer   ~50205

My filename was äöü.png ;) , but my locale is OK.

Can show your current locale in PHP ?


2019-01-15 10:37

reporter   ~50207

Sorry, I misread your screenshot and thought the left column were the filenames, my bad.

phpinfo() gives me:

It's still strange why only umlauts at the beginning get stripped off. This should not be locale dependent!


2021-03-10 22:43

administrator   ~63212

Please update to the latest version and check if the bug can still be reproduced. Thank you.


2021-03-11 10:40

reporter   ~63290

I can confirm this is still broken in Version 3.25.17+210309.
Attached is a sample survey+file. Uploading the file results in a file name "sterreich.png"


setlocale(LC_ALL, 'en_US.UTF8');

in index.php still fixes it.
österreich.png (861 bytes)   
österreich.png (861 bytes)   

Issue History

Date Modified Username Field Change
2018-09-24 16:21 tbart New Issue
2019-01-10 17:40 LouisGac Assigned To => LouisGac
2019-01-10 17:40 LouisGac Status new => closed
2019-01-10 17:40 LouisGac Resolution open => no change required
2019-01-10 17:40 LouisGac Note Added: 50169
2019-01-14 17:40 tbart Note Added: 50188
2019-01-15 08:40 DenisChenu Status closed => feedback
2019-01-15 08:40 DenisChenu Resolution no change required => reopened
2019-01-15 08:40 DenisChenu Note Added: 50192
2019-01-15 08:40 DenisChenu File Added: Capture d’écran du 2019-01-15 08-40-13.png
2019-01-15 08:51 DenisChenu Note Edited: 50192 View Revisions
2019-01-15 09:06 tbart File Added: umlauts_at_the_beginning_cut_off.png
2019-01-15 09:06 tbart Note Added: 50194
2019-01-15 09:06 tbart Status feedback => assigned
2019-01-15 10:00 DenisChenu Note Added: 50205
2019-01-15 10:37 tbart Note Added: 50207
2021-03-10 22:43 ollehar Assigned To LouisGac =>
2021-03-10 22:43 ollehar Status assigned => feedback
2021-03-10 22:43 ollehar Note Added: 63212
2021-03-11 10:40 tbart Note Added: 63290
2021-03-11 10:40 tbart File Added: limesurvey_survey_185162.lss
2021-03-11 10:40 tbart File Added: österreich.png
2021-03-11 10:40 tbart Status feedback => new
2021-03-11 11:38 ollehar Priority none => high