otherwise we cannot use ftp to create new subdirectories and files in root, as mention

oh, btw, <a class="user-mention notranslate" data-hovercard-type="user" data-hovercard

So, we are running vsftpd version 3.0.3 <a target="_blank" rel="noopener noreferre

can we somehow allow an anonymously writable ftp root? about fluffi HOT 5 CLOSED

p0wer0xff commented on July 20, 2024

can we somehow allow an anonymously writable ftp root?

from fluffi.

Comments (5)

p0wer0xff commented on July 20, 2024 1

oh, btw, @maverickwoo you might be interested in this, since you originally brought it to my attention.

from fluffi.

TomSie commented on July 20, 2024

now that the documentation is updated, do we still need this?

from fluffi.

p0wer0xff commented on July 20, 2024

probably not for our use case, but it vexes me that v(ery)s(tupid)ftpd does not seem to mind allow_writeable_chroot=YES at all.

also, if someone wants to extend FLUFFI and needs new directories, it's just inconvenient not to have a writable root.

from fluffi.

TomSie commented on July 20, 2024

Given that there is no easy fix, and the need for this feature is minimal, I would close this issue as won't fix for now. Is that fine with you?

from fluffi.

p0wer0xff commented on July 20, 2024

So, we are running vsftpd version 3.0.3

from the ubuntu repositories for 18.04 as per Dockerfile to which the sources are located here

My initial gut feeling was that the packaging people at ubuntu/debian might have disabled the option for security, but the only patch that touches the subject is debian/patches/0060-seccomp_sandbox.patch which sets the default value at compile time to tunable_allow_writeable_chroot = 0;

because in several search results on google there are inconsistencies concerning what the config option is supposed to be called, looking into the vsftpd source, we find the correct spelling of the option in parseconf.c

109   { "allow_writeable_chroot", &tunable_allow_writeable_chroot },

so it is actually set when present in the config file. Next, we find the error message in secutil.c:

132   /* Misconfiguration check: don't ever chroot() to a directory writable by                                                                                                                                     
133    * the current user.                                                                                                                                                                                          
134    */                                                                                                                                                                                                           
135   if ((options & VSF_SECUTIL_OPTION_CHROOT) &&                                                                                                                                                                  
136       !(options & VSF_SECUTIL_OPTION_ALLOW_WRITEABLE_ROOT))                                                                                                                                                     
137   {                                                                                                                                                                                                             
138     if (vsf_sysutil_write_access("/"))                                                                                                                                                                          
139     {                                                                                                                                                                                                           
140       die("vsftpd: refusing to run with writable root inside chroot()");                                                                                                                                        
141     }                                                                                                                                                                                                           
142   }

which leads us back to twoprocess.c:

452     if (!was_anon && tunable_allow_writeable_chroot)                                                                                                                                                            
453     {                                                                                                                                                                                                           
454       secutil_option |= VSF_SECUTIL_OPTION_ALLOW_WRITEABLE_ROOT;                                                                                                                                                
455     }

So we learn a seemingly common misunderstanding (looking at the dozens of search results on the topic and no working answer), namely that vsftpd does not allow writable chroot at all when using anonymous login and the chrooting security mechanism, no matter if the config option is set or not. The only conceivable way to reach our goal here might be to disable the chrooting behavior, but that might entail more investigation into consequences.

With these results I'm closing this as wontfix, though I do so begrudgingly.

from fluffi.

can we somehow allow an anonymously writable ftp root? about fluffi HOT 5 CLOSED

Comments (5)

Related Issues (20)

Recommend Projects

React

Vue.js

Typescript

TensorFlow

Django

Laravel

D3

Recommend Topics

javascript

web

server

Machine learning

Visualization

Game

Recommend Org

Facebook

Microsoft

Google

Alibaba

D3

Tencent