Connection to server lost on certain filenames in Firefox

[KreativeKrise]

Steps to reproduce

1. Create a file with "*728x90.ext" or "*160x600.ext" (e.g. "lala_728x90.txt" or "160x600.jpg") as name. The format or extension of the file doesn't matter.
2. Upload the file using Firefox

Expected behaviour

The file should be stored on the server.

Actual behaviour

The message "Connection to server lost" appears and file was not stored on the server.

Server configuration

Operating system:
Linux 4.9.12-gs #2 SMP Sat Feb 25 21:06:56 CET 2017 x86_64

Web server:
Apache (fpm-fcgi)

Database:
mysql 10.0.30

PHP version:
7.0.18
Modules loaded: Core, date, libxml, openssl, pcre, zlib, bz2, calendar, ctype, hash, filter, ftp, gettext, gmp, SPL, iconv, Reflection, session, standard, SimpleXML, sockets, mbstring, tokenizer, xml, cgi-fcgi, mysqlnd, apcu, bcmath, curl, dba, dom, enchant, fileinfo, gd, imagick, imap, intl, json, ldap, exif, mcrypt, mysqli, odbc, PDO, pdo_mysql, PDO_ODBC, pdo_pgsql, pdo_sqlite, pgsql, Phar, posix, pspell, redis, soap, sqlite3, sysvmsg, sysvsem, sysvshm, tidy, xmlreader, xmlrpc, xmlwriter, xsl, zip, ionCube Loader, Zend OPcache

Nextcloud version:
11.0.3 (stable) - 11.0.3.2

Updated from an older Nextcloud/ownCloud or fresh install:
fresh install

Where did you install Nextcloud from:
nextcloud.com

List of activated apps:

App list

``` - activity: 2.4.1 - comments: 1.1.0 - dav: 1.1.1 - federatedfilesharing: 1.1.1 - federation: 1.1.1 - files: 1.6.1 - files_pdfviewer: 1.0.1 - files_sharing: 1.1.1 - files_texteditor: 2.2 - files_trashbin: 1.1.0 - files_versions: 1.4.0 - files_videoplayer: 1.0.0 - firstrunwizard: 2.0 - gallery: 16.0.0 - issuetemplate: 0.2.1 - logreader: 2.0.0 - lookup_server_connector: 1.0.0 - nextcloud_announcements: 1.0 - notifications: 1.0.1 - password_policy: 1.1.0 - provisioning_api: 1.1.0 - serverinfo: 1.1.1 - sharebymail: 1.0.1 - survey_client: 0.1.5 - systemtags: 1.1.3 - theming: 1.1.1 - twofactor_backupcodes: 1.0.0 - updatenotification: 1.1.1 - workflowengine: 1.1.1 ```

List of deactivated apps:

App list

``` - admin_audit - encryption - external - files_accesscontrol - files_automatedtagging - files_external - files_retention - templateeditor - user_external - user_ldap - user_saml ```

The content of config/config.php:

Config report

``` { "instanceid": "ocm9cfsgobyy", "passwordsalt": "***REMOVED SENSITIVE VALUE***", "secret": "***REMOVED SENSITIVE VALUE***", "trusted_domains": [ "share.handbuch-experten.de" ], "datadirectory": "\/var\/www\/vhosts\/handbuch-experten.de\/share.handbuch-experten.de\/data", "overwrite.cli.url": "https:\/\/share.handbuch-experten.de", "dbtype": "mysql", "version": "11.0.3.2", "dbname": "admin_handbuchexperten_nextcloud", "dbhost": "localhost", "dbport": "", "dbtableprefix": "oc_", "dbuser": "***REMOVED SENSITIVE VALUE***", "dbpassword": "***REMOVED SENSITIVE VALUE***", "logtimezone": "UTC", "installed": true, "updater.secret": "***REMOVED SENSITIVE VALUE***", "maintenance": false, "theme": "", "loglevel": 2, "memcache.local": "\\OC\\Memcache\\APCu", "memcache.locking": "\\OC\\Memcache\\Redis", "redis": { "host": "127.0.0.1", "port": 6379 } } ```

Are you using external storage, if yes which one:
files_external is disabled

Are you using encryption:
no

Client configuration

Browser:
Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:53.0) Gecko/20100101 Firefox/53.0

Operating system:
Microsoft Windows 10

Logs

Web server error log

nothing relevant

Nextcloud log (data/nextcloud.log)

nothing relevant

Browser log

nothing relevant

[Stibila]

I experience exactly same problem with NC 11 and php 7.1.4

I tried NC 12 beta in testing environment with php 7.0.15 and php 5.6.3 with same result each time. I tried only filename lala_728x90.txt so I can't confirm if this problem occurs with others.

[hkahl]

I can confirm that with nextcloud 11.0.3 (stable).
This is not limited to Firefox. I also tested Chrome. Both on Linux.

• cannot upload 'lala_728x90.txt'

Tested creating directories:

• cannot create directory 'Advertising_P_PICTURES'

• cannot create directory 'Advertising_P'

• cannot create directory 'Advertising_X'

• cannot create directory 'Advertising_'

• successfully created directory 'Advertisin_P'

• successfully created directory 'Advertisinn_P'

There are a lot of directories on my server that I am not able to open anymore through nextcloud.
I always get the message "connection to server lost". I set the nextcloud log level to debug, but nothing appears in the logs.

[hkahl]

Adblock Plus seems to cause the issue. That's why creating a directory with 'Advertising' in the name was not possible. Strange that somthing like 'lala_728x90.txt' is blocked by ADP.

Anyway, disabling Adblock Plus or adding the nextcloud server to the whitelist resolved the issue.