Is it possible to somehow view another websites php files/codes?
Or to rephrase the question, Can my php codes be viewed by anybody except for those who have access to the file?
If so, how can I best prevent this?
Ps: Server OS is Ubuntu 9.10 and PHP version is 5+ (Apache2)
A bug or security vulnerability in the server (either Apache or the PHP engine), or your own PHP code, might allow an attacker to obtain access to your code.
For instance if you have a PHP script to allow people to download files, and an attacker can trick this script into download some of your PHP files, then your code can be leaked.
Since it's impossible to eliminate all bugs from the software you're using, if someone really wants to steal your code, and they have enough resources, there's a reasonable chance they'll be able to.
However, as long as you keep your server up-to-date, someone with casual interest is not able to see the PHP source unless there are some obvious security vulnerabilities in your code.
Read the Security section of the PHP manual as a starting point to keeping your code safe.
By using exploits or on badly configured servers it could be possible to download your PHP source. You could however either obfuscate and/or encrypt your code (using Zend Guard, Ioncube or a similar app) if you want to make sure your source will not be readable (to be accurate, obfuscation by itself could be reversed given enough time/resources, but I haven't found an IonCube or Zend Guard decryptor yet...).
Noone cand read the file except for those who have access to the file. You must make the code readable (but not writable) by the web server. If the php code handler is running properly you can't read it by requesting by name from the web server.
If someone compromises your server you are at risk. Ensure that the web server can only write to locations it absolutely needs to. There are a few locations under /var which should be properly configured by your distribution. They should not be accessible over the web. /var/www should not be writable, but may contain subdirectories written to by the web server for dynamic content. Code handlers should be disabled for these.
Ensure you don't do anything in your php code which can lead to code injection. The other risk is directory traversal using paths containing .. or begining with /. Apache should already be patched to prevent this when it is handling paths. However, when it runs code, including php, it does not control the paths. Avoid anything that allows the web client to pass a file path.
Related
I am replacing an existing very old site written in another lang with a newly-coded php site and I need to double-check a couple of things with respect to security. Website will be running on Windows 2008 R2 using IIS 7.5 and running php 5.3.8.
I am storing db login creds in a file outside of web root. But in my php code I have to include those files and I am using an absolute path. Will php and/or IIS strip out the file path. (I imagine the answer is yes since competing technologies would do likewise, but need to be sure on this and couldn't find the answer.)
On a related point, what is the best place to keep .js files? Is it better security-wise to keep them outside of web root?
Sorry for the basic questions, but am new to php (long time programmer in other langs).
well, php is different from ASP, so my suggestion is to make a subdomain for js/css, you even can name it CDN... but, it still better than from the root.
I ran a bunch of tests where I looked at the source of what is returned by php and the webserver. If you use the php command "require c:\abc\file.php" neither piece of information is returned with the html.
However, the path to a .js file IS displayed. This is because it sits inside the html, not php, so that path is NOT stripped out by php or the webserver.
So from this I think I can safely say:
1. The path to the creds will not be displayed in the html source returned to the browser or curl call or whatever.
2. js and css paths are shown publicly so it is worth considering whether these need to be secured (e.g., separate subdomain or similar).
I have a doubt about PHP, Apache, server interpretation... I know that when a PHP file is loaded by the browser from an Apache+PHP server it is interpreted and only the HTML and plain text is showed but is there a way to download this files instead of interpreting them?
In this case it would be very unsecure because MySQL passwords would be unsafe.
Is it any security measure to prevent this or it's impossible to download this files?
As long as your server is setup properly it isn't going to happen.
A good step though is to put all of your actual passwords and whatnot in a config.php and including it. That way you can use htacces too block that file so that should your server ever start serving the raw pages that file won't be accessible anyway.
To clarify if you create a .htaccess file and place it in the same folder as the config.php with the below information that file will not be served, even if requested directly. Simply define your config stuff (db name, user name, password, hashes, etc) in this file and include_once it at the top of each page that needs it and you will be good to go.
<files config.php>
order allow,deny
deny from all
</files>
There is no way to 'download' PHP files, but for more security you can place your 'core' PHP files outsite of the public_html folder
Unless the PHP interpreter stops working for some reason, it's not something to worry about. Most servers are designed to interpret the PHP files every time they are requested and serve only the interpreted HTML text. It's possible to secure your sensitive PHP settings files just in case - often by placing them outside of the root directory with modified permissions.
The only way someone could download the files is to have a server set up that serves the raw files. As long as you don't have such a server set up, they're inaccessible. If the only server software on your system is Apache and it's configured correctly, people cannot see your source code.
However, if somebody seeing your source would render your app vulnerable, you might want to give some thought as to how you can fix that problem. Lots of secure open-source software exists — why would yours being open-source cause problems?
With proper configuration apache guarantees that files will always get interpreted and won't be offered for download.
You always may install fault update or make wrong configuration, but with skilled admin and stable release those cases just don't happen.
I'm currently developing a PHP framework. Other developers may create modules for the framework. Source code of these modules should reside in the framework directory.
Since the project is open-source, modules know location of the config file which has database password in it. How to protect passwords from malicious modules? Please check that modules may just require_once the config file and do harmful things!
Currently I'm storing Database passwords in a directory named config, and protecting it by a .htaccess file:
<Directory config>
order allow,deny
deny from all
<Directory>
But that is not sufficient to prevent scripts steal the password, is it?
I've read the thread How to secure database passwords in PHP? but it did not help me finding the answer.
In PHP, you can't. It's not a sandboxed language; any code you run gets all the permissions of the user it's running under. It can read and write files, execute commands, make network connections, and so on, You must absolutely trust any code you're bringing in to your project to behave well.
If you need security boundaries, you would have to implement them yourself through privilege separation. Have each module run in its own process, as a user with very low privileges. Then you need some sort of inter-process communication. That could be using OS-level pipes, or by having separate .php files run as different users running as web services accessed by the user-facing scripts. Either way, it doesn't fit neatly into the usual way PHP applications work.
Or use another language such as Java, which can offer restricted code with stronger guarantees about what it is allowed to do (see SecurityManager et al).
Unfortunately, PHP is not a very secure language or runtime. However, the best way to secure this sort of information is to provide a configuration setting that has your username/password in it, outside of your document root. In addition, the modules should just use your API to get a database connection, not create one of their own based on this file. The config setting should not be global. You should design something like this in a very OOP style and provide the necessary level of encapsulation to block unwarranted access.
I've got an idea that may work for you, but it all really depends on what abilities your framework scripts have. For my idea to be plausible security wise you need to essentially create a sandbox for your framework files.
One idea:
What you could do (but probably more resource intensive) is read each module like you would a text file.
Then you need to identify everywhere that reads a file within their script. You've got things like fopen for file_get_contents to consider. One thing I'd probably do is tell the users they may only read and write files using file_get_contents and file_put_contents, then use a tool to strip out any other file write/read functions from their script (like fopen).
Then write your own function to replace file_get_contents and file_put_contents, make their script use your function rather than PHP's file_get_contents and file_put_contents. In your file_get_contents function you're essentially going to be checking permissions; are they accessing your config file, yes or no, then return a string saying "access denied" if they are or you use the real file_get_contents to read and return the file if not.
As for your file_put_contents, you just need to make sure they're not writing files to your server (they shouldn't be allowed, imagine what they could do!), alternatively, you could probably use a CHMOD to stop that happening.
Once you've essentially rewritten the module in memory, to be secure, you then use the "exec" function to execute it.
This would take a considerable amount of work - but it's the only pure PHP way I can think of.
I am not sure if it is possible, however you could maybe make a system which checks the files in the module for any php code which tries to include the config file, and then warn the user about it before installing.
However it really shouldn't be your responsibility in the end.
A very good question with no good answer that I know of, however...
Have you seen runkit? It allows for sandboxing in PHP.
The official version apparently isn't well maintained any more, however there is a version on GitHub that is quite popular: zenovich/runkit on GitHub
Although the best solution is perhaps a community repository where every submission is checked for security issues before being given the OK to use.
Good Luck with your project
Well, I see no problem here.
If it's a module, it can do harmful things by definition, with or without database access. It can delete files, read cookies, etc etc.
So, you have to either trust to these modules (may be after reviewing them) or refuse to use modules at all.
Don't include your actual config file in your open source project.
The way I do it is a create just the template config file config.ini.dist
When a user downloads your project they have to rename it to config.ini and enter their own configuration information.
This way every user will have their own database connection info like username and password. Also when you update your project and users download your newest version, their own config files will not be overwritten by the one from your program.
This a a very common way to store configuration in open source projects - you distribute a template config file and tell users that they have to rename it and enter their own configuration details.
I don't think there is a way to prevent a module to capture sensible data from the actual framework configuration and send it to some stranger out there. On the other end, I don't think that should be your responsability to protect the user from that to happen.
After all, it's the user that will decide to install any module, right? In theory it should be him that would have to verify the module intents.
Drupal, for example, does nothing in this direction.
There is a worst problem, anyway: what'd prevent a nasty module to wipe out your entire database, once it is installed?
And, by the way, what could the malicious stranger do with your database password? At the very least you anyway need to secure the connection of the database, so that only trusted hosts can connect to the database server (IP/host based check, for example).
im trying to implement on my site a system who let the user download a file that have to be change before the download.
I have a master file (a .exe program), that inside have a variable who has to be change for every different user.
The most simple solution is to change a variable inside a xml file every time the user want his personalized exe and then make the exe file to read the external file. BUT i dont want the user to download more than one file.
Is this possible? using php can i change a parametter inside a compiled program? Thanks for any help and suggestions!
If you really really know what you're doing and you know exactly the bits that need to be flipped inside the file, then yes, it's possible to modify the .exe file with PHP. Otherwise you have to make changes to the source or other files the .exe is built with and compile the program on the server before sending it to the user.
In theory it's certainly possible (PHP is turing complete), but as stated in other answers it will be hardly worth the hassle (considering the fact that you have to ask whether it is possible shows you'd have to investigate at last for days into the standard exe-format).
I'd recommend one of the following:
1) Zip the program with the configuration file; either use a separate launcher (e.g. Java [a JAR is a ZIP file]) or add a configuration file that is read by the program itself. There is a number of PHP libraries for generating ZIP files.
2) compile the program with the changed source on the server itself; however this can also become quite complicated depending on your server configuration and the programming environment you use. If you have never administered a virtual server I would not even slightly recommend that as an option.
3) If you can assume that the user got somewhat stable Internet access you might also consider to let hir download a standard executable, where additional configuration will be downloaded later on by the program itself (e.g. by transmitting the username to the server). However this creates dependencies you might want to avoid (your user probably can't use it on machines without Internet access and you should assert that your server is up most of the time).
While it's probably possible, I doubt it's worth the hassle. Unless you're trying to fight piracy or something. Why don't you just serve the user a custom .zip file with the .exe and a config .xml?
[edit after OP commented]
I presume what you're trying to edit is the facebook ID/username? Well, try to compile the base file with some unique string like "THISNEEDSTOBEREPLACED", then use some binary safe function to replace it. Though remember things can and will get tricky if the string lengths don't match.
Is it possible to download php files from the server where they are located? I am a beginner in web area, and I worry that hackers may have special tools to download, see my code and understand where I have programmed vulnerable codes to hack my site.
If the server is properly configured and there are no security holes in the code then no, it's not possible.
If you have something like
echo file_get_contents($_GET['myFile']);
then this could be used to get your code - never do this!
In 9/10 cases the way bad guys can download your php source code is if you keep backup files in the webroot, things like foo.php.bak or foo.php.old or .backup. These are served as plain files by default so be careful of this issue in addition to the above suggestions.
It's not possible to directly download the source to your php files which are processed through Apache, unless your web server for whatever reason suddenly broke and stopped serving php files through the php interpreter ( if you were messing around with the settings perhaps and broke it. )
A very skilled cracker would probably be able to infiltrate your web server though, and easily download anything on it, but the chances of this are very, very low. If you're not some big company then who would care to take the time to really hack you?
Another point to make is whenever you're dealing with user input, always sanitize otherwise you'd be susceptible to common XSS attacks ( escape strings, dont rely on PHP_SELF, plenty of other sanitisation that can be done ).
the configuration of the webserver determined if a file should be parsed to the php parser or not. this is usually based on the file extention. So, files ending on .php would be parsed, and for php source you would use .phps. So .php files, on the webserver to generate dynamic content can't be downloaded as source.
Hackers don't need your source code to break into your site. In fact the majority of the vulnerabilities on OWASP top 10 doesn't require source code to exploit:
http://www.owasp.org/index.php/Top_10_2007
"Black Box" vulnerabilities scanners like Acunetix (http://www.acunetix.com) Or the open source project Wapiti (http://wapiti.sourceforge.net) can uncover SQL Injection, XSS and Source Code Disclosure vulnerabilities easily. Its a great tool.