Upload pictures : Exif dimensions used instead of real image size

Hi.

Abstract

When a user upload a resized picture, phpbb use original filesize (exif data) and not real size of  picture.

Context :

phpbb3.2.1 with upload file restrictions set up as :

max size : 1024 x 1024 pixels

max file size : 1 Mb

Several users claims since 3.2.1 update they can not post pictures altought they are conform.

File example : http://www.greffer.net/images/uploads/test.jpg
Size 465x830 pix, 280 ko

When I upload with my admin account, no error.
But, if I upload as simple user privilege, at the end of file upload, a error appears, saying that maximum size is 1024x1024 but the file uploaded is : 3920 x 2204.

I test this file with a php test file with getimagesize function , itreturns :

 Array ( [0] => 465 [1] => 830 [2] => 2 [3] => width="465" height="830" [bits] => 8 [channels] => 3 [mime] => image/jpeg )

 The file image dimensions seems perfect.

On french phpbb help forums, some others users have the same problem.

It seems, if this data is available, that phpbb use EXIF image size and not picture real size (the original picture has been resized by the user, EXIT data contains original size, not size after resizing).

Exif data of this picture :

File size       : 280810 Bytes

MIME type       : image/jpeg

Image size      : 465 x 830

Camera make     : Sony

Camera model    : E2303

Image timestamp : 2017:09:09 13:25:12

Image number    : 

Exposure time   : 1/132 s

Aperture        : F2

Exposure bias   : 0 EV

Flash           : No, auto

Flash bias      : 

Focal length    : 3.6 mm

Subject distance: Unknown

ISO speed       : 100

Exposure mode   : Not defined

Metering mode   : Center weighted average

Macro mode      : 

Image quality   : 

Exif Resolution : 3920 x 2204

White balance   : Auto

Thumbnail       : image/jpeg, 4600 Bytes

Copyright       : 

Exif comment    : 

 Image size and exif resolution are not egal.

When I erase exif data exiv2 software, the upload is not OK.

Best regards.