Delicious Bookmark this on Delicious Share on Facebook SlashdotSlashdot It! Digg! Digg



PHP : Features : Safe Mode : Functions restricted/disabled by safe mode

Functions restricted/disabled by safe mode

This is a still probably incomplete and possibly incorrect listing of the functions limited by safe mode.

Table 9.2. Safe mode limited functions

Function Limitations
dbmopen() Checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed.
dbase_open() Checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed.
filepro() Checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed.
filepro_rowcount() Checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed.
filepro_retrieve() Checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed.
ifx_* sql_safe_mode restrictions, (!= safe mode)
ingres_* sql_safe_mode restrictions, (!= safe mode)
mysql_* sql_safe_mode restrictions, (!= safe mode)
pg_lo_import() Checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed.
posix_mkfifo() Checks whether the directory in which you are about to operate has the same UID (owner) as the script that is being executed.
putenv() Obeys the safe_mode_protected_env_vars and safe_mode_allowed_env_vars ini-directives. See also the documentation on putenv()
move_uploaded_file() Checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed.
chdir() Checks whether the directory in which you are about to operate has the same UID (owner) as the script that is being executed.
dl() This function is disabled in safe mode.
backtick operator This function is disabled in safe mode.
shell_exec() (functional equivalent of backticks) This function is disabled in safe mode.
exec() You can only execute executables within the safe_mode_exec_dir. For practical reasons it's currently not allowed to have .. components in the path to the executable. escapeshellcmd() is executed on the argument of this function.
system() You can only execute executables within the safe_mode_exec_dir. For practical reasons it's currently not allowed to have .. components in the path to the executable. escapeshellcmd() is executed on the argument of this function.
passthru() You can only execute executables within the safe_mode_exec_dir. For practical reasons it's currently not allowed to have .. components in the path to the executable. escapeshellcmd() is executed on the argument of this function.
popen() You can only execute executables within the safe_mode_exec_dir. For practical reasons it's currently not allowed to have .. components in the path to the executable. escapeshellcmd() is executed on the argument of this function.
fopen() Checks whether the directory in which you are about to operate has the same UID (owner) as the script that is being executed.
mkdir() Checks whether the directory in which you are about to operate has the same UID (owner) as the script that is being executed.
rmdir() Checks whether the directory in which you are about to operate has the same UID (owner) as the script that is being executed.
rename() Checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed. Checks whether the directory in which you are about to operate has the same UID (owner) as the script that is being executed.
unlink() Checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed. Checks whether the directory in which you are about to operate has the same UID (owner) as the script that is being executed.
copy() Checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed. Checks whether the directory in which you are about to operate has the same UID (owner) as the script that is being executed. (on source and target)
chgrp() Checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed.
chown() Checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed.
chmod() Checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed. In addition, you cannot set the SUID, SGID and sticky bits
touch() Checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed. Checks whether the directory in which you are about to operate has the same UID (owner) as the script that is being executed.
symlink() Checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed. Checks whether the directory in which you are about to operate has the same UID (owner) as the script that is being executed. (note: only the target is checked)
link() Checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed. Checks whether the directory in which you are about to operate has the same UID (owner) as the script that is being executed. (note: only the target is checked)
apache_request_headers() In safe mode, headers beginning with 'authorization' (case-insensitive) will not be returned.
header() In safe mode, the uid of the script is added to the realm part of the WWW-Authenticate header if you set this header (used for HTTP Authentication).
PHP_AUTH variables In safe mode, the variables PHP_AUTH_USER, PHP_AUTH_PW, and AUTH_TYPE are not available in $_SERVER. Regardless, you can still use REMOTE_USER for the USER. (note: only affected since PHP 4.3.0)
highlight_file(), show_source() Checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed. Checks whether the directory in which you are about to operate has the same UID (owner) as the script that is being executed. (note: only affected since PHP 4.2.1)
parse_ini_file() Checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed. Checks whether the directory in which you are about to operate has the same UID (owner) as the script that is being executed. (note: only affected since PHP 4.2.1)
set_time_limit() Has no effect when PHP is running in safe mode.
max_execution_time Has no effect when PHP is running in safe mode.
mail() In safe mode, the fifth parameter is disabled. (note: only affected since PHP 4.2.3)
Any function that uses php4/main/fopen_wrappers.c ??


Code Examples / Notes » features.safe_mode.functions

zauker
The SAFE_MODE handling of glob() needs a checkup for security reasons.
In short - always with SAFE_MODE on:
1) glob() can still fetch all filenames in a directory not owned by the
same UID as the user, if just the first file in the directory (or more
specific, the glob-pattern) happens to be owned by the same user as the
PHP-script.
2a) No warning is raised if glob is used on another owner's directory
and there is no match.
2b) In those cases where SAFE_MODE correctly prohibits glob() from
fetching a list of files, the warning still discloses the first
filename.
Solution: glob() in SAFE_MODE should be restricted in the same way as
opendir() is
see the link http://bugs.php.net/bug.php?id=28932

tschmieder
refers to the previuos posting of
bananarama
15-May-2006 10:11
"all file-handling and -management functions are restricted, just in case someones wondering why they're not listed here.
a script can run these functions on files without errors, if the files were created (are owned) by the same UID, the script was created (is owned) by."
.... or if the directory, in which the file is located, has the same UID as the script, which tries to use a file in that directory...

lionel
readfile() is probably also limited by safe mode

jan
It seems that glob and file_exists functions are also restricted in safe-mode.

bananarama
all file-handling and -management functions are restricted, just in case someones wondering why they're not listed here.
a script can run these functions on files without errors, if the files were created (are owned) by the same UID, the script was created (is owned) by.
example:
you upload a script, it is owned by UID 720. you upload a picture, it is owned by UID 720. the script creates a thumbnail of the picture. the thumb is owned by UID 30 (the server/apache). this makes it impossible (?) to run a gallery script, which checks for newly uploaded pictures in order to create and display thumbs of them if you want to check, if a thumbnail already exists. the script would be owned by UID 720, the thumb by UID 30.
you could upload a script which creates a file (e.g. from a text file) with .php ending. this script would be owned by UID 30 and could access the thumbs, but it couldnt read the upload pictures.
<?
 $data = fread(fopen("test.txt", "r"), filesize("test.txt"));
 
 $file = "test.php";  
 if (!$file_handle = fopen($file,"a")) { echo "Cannot open file"; }  
 if (!fwrite($file_handle, $data)) { echo "Cannot write to file"; }    
 fclose($file_handle);
 
 chmod("test.php", 0777);
?>

Change Language


Follow Navioo On Twitter
Security and Safe Mode
Functions restricted/disabled by safe mode
Terms of Service Privacy Policy Sitemap

©2024 -EPSILONSYS SOFTWARE inc

Other EPSILONSYS SOFTWARE Web Sites : Programming Resources | News Headline | Free local classifieds

eXTReMe Tracker