Bean html modules php name. Jdoc:include - method for displaying content on a page
The em element represents a piece of text with an underlined accent. You can use it to draw the reader's attention to the meaning of a sentence or paragraph. I'll tell you what it means after the , which describes the em element.
Table 8-6: em element
Figure 8-3: Using the em element
In this example, I put the emphasis on I (I) at the beginning of the sentence. Thinking about the em element, when we say a sentence aloud, we consider that the sentence is an answer to a question. For example, imagine I asked, "Who likes apples and oranges?" Your answer will be: "I like apples and oranges." (When you say this out loud and put the emphasis on I, you make it clear that you are a person who loves these fruits).
But if I asked: "Do you like apples and what else?" You could answer, "I like apples and oranges." In this case, the emphasis will be on the last word, emphasizing that oranges are another fruit that you enjoy. This HTML version would look like this:
I like apples and oranges .
Definition of foreign words and technical terms
The i element denotes a piece of text that is of a different nature than the surrounding content. This is a rather vague definition, but common examples include words from other languages, technical or scientific terms, and even human thoughts (as opposed to speech). In the element i is described.
Table 8-7: Element i
Figure 8-5: Using the s element
Definition of important text
The strong element denotes a passage of text that has importance. This element is described in.
Table 8-9: strong element
Figure 8-7: Using the u element
Adding small print
The small element denotes small print and is often used for disclaimers and clarifications. The small element is represented in .
Table 8-11: small element
Figure 8-8: Using the small element
Adding superscript and subscript
You can use the sub and sup elements to indicate superscript and subscript, respectively. Superscripts are used to write words in some languages, and both superscript and subscript are used in simple mathematical expressions. These elements are presented.
Table 8-12: sub and sup elements
Figure 8-9: Using sub and sup elements
One of PHP's biggest strengths is how it works with HTML forms. The key here is that each form element is automatically made available to your PHP programs. For detailed information see the section on using forms in PHP. Here is an example of an HTML form:
Example #1 The simplest HTML form
There is nothing special about this form. This is a normal HTML form without any special tags. When the user fills out the form and clicks the submit button, the action.php page will be called. This file might contain something like:
Beispiel #2 Rendering form data
Hello,
.
To youyears.
Sample output from this program:
Hello Sergey. You are 30 years old.
If you do not take into account pieces of code with htmlspecialchars() and (int), the principle of operation of this code should be simple and clear. htmlspecialchars() ensures that "special" HTML characters are properly encoded so that malicious HTML or Javascript is not inserted into your page. The age field, which we know must be a number, we can simply convert to integer, which will automatically get rid of unwanted characters. PHP can also do this automatically with the filter extension. The $_POST["name"] and $_POST["age"] variables are automatically set for you means of PHP. Earlier we used the $_SERVER superglobal, but here we also use the $_POST superglobal, which contains all the POST data. notice, that sending method(method) of our form is POST. If we were to use the method GET, then our form information would be in the $_GET superglobal. Alternatively, you can use the $_REQUEST variable if the data source is irrelevant. This variable contains a mix of GET, POST, COOKIE data.
15 years ago
According to the HTTP specification, you should use the POST method when you"re using the form to change the state of something on the server end. For example, if a page has a form to allow users to add their own comments, like this page here, the form should use POST. which is why these pages aren't bookmarked or cached.
You should use the GET method when your form is, well, getting something off the server and not actually changing anything. For example, the form for a search engine should use GET, since searching a Web site should not be changing anything that the client might care about, and bookmarking or caching the results of a search-engine query is just as useful as bookmarking or caching a static HTML page.
2 years ago
Worth clarifying:
POST is not more secure than GET.
The reasons for choosing GET vs POST involve various factors such as intent of the request (are you "submitting" information?), the size of the request (there are limits to how long a URL can be, and GET parameters are sent in the URL), and how easily you want the Action to be shareable -- Example, Google Searches are GET because it makes it easy to copy and share the search query with someone else simply by sharing the URL.
Security is only a consideration here due to the fact that a GET is easier to share than a POST. Example: you don't want a password to be sent by GET, because the user might share the resulting URL and inadvertently expose their password.
However, a GET and a POST are equally easy to intercept by a well-placed malicious person if you don't deploy TLS/SSL to protect the network connection itself.
All Forms sent over HTTP (usually port 80) are insecure, and today (2017), there aren't many good reasons for a public website to not be using HTTPS (which is basically HTTP + Transport Layer Security).
As a bonus, if you use TLS you minimize the risk of your users getting code (ADs) injected into your traffic that wasn't put there by you.
There is a common vulnerability of the PHP-inclusion class. But, the person for whom I did the audit told me that this vulnerability cannot be exploited, so it does not count. I had to argue with him.
What is PHP-include
Let's conduct a small educational program on this vulnerability. PHP-include is a vulnerability that allows you to "include" an arbitrary file, for example, this code:
$module=$_REQUEST["module"]; include("modules/".$module);
And since there are usually no php tags in the "/etc/passwd" file (), then it will be displayed in the browser, as it would be displayed html code rendered behind php tags in normal php script. Of course, reading files is just one of the possible implementations of this attack. The main thing is inclusion desired files with the required php code.
Let's go back to the example. Let's complicate it:
$module=$_REQUEST["module"]; include("modules/".$module."/module.class.php");
$module = $_REQUEST [ "module" ] ; include ("modules/" . $module . "/module.class.php" ) ; |
As you can see, now a line is added to our variable at the end, which prevents us from including any file. So, many php functions are not binary safe, i.e. such functions consider NULL-byte as the end of the string. We refer to the script like this:
script.php?module=../../../../../../../../../../../etc/passwd%00
And if the magic_quotes directive is disabled, then we will again see the contents of /etc/passwd
Is there a vulnerability?
Let's go back to our code:
$module=addslashes($_REQUEST["module"]); include("modules/".$module."/module.class.php");
$module = addslashes ($_REQUEST [ "module" ] ) ; include ("modules/" . $module . "/module.class.php" ) ; |
As you can see, our variable is forcibly passed through "addslashes" and if we try to use a NULL byte, it will be converted to "\0" and the include will not work.
But progress does not stand still! It turns out some guys from USH have found an interesting feature in PHP PHP filesystem attack vectors. In short, to retell the essence of the article, then php processes paths using several features:
- Path Truncation- php truncates the path string to the given length MAXPATHLEN (On Windows up to 270 characters, on NIX - usually 4096, on BSD - usually 1024)
- Path normalization- php handles the path in a special way, removing extra characters "/" and "/." and their various combinations
- Reduction to canonical form- extra transitions are removed, for example, "dir1/dir2/../dir3" is reduced to "dir1/dir3/" while the existence of the "dir2" directory is not checked, and other similar transformations (i.e. continuation of normalization)
Now, in order, what happens to the passed path:
- If the path is relative, then the values from the include_path directive are first substituted for it
- Next, the path is trimmed to a certain length depending on the platform
- Path normalization in progress
- The path is reduced to the canonical form
Now let's try to use this. Let's try to include some file "test.php" which is located in the "modules/" directory. To do this, add "/." to the end of the character. so that the total length, together with the file name, the value from include_path, must be more than 4096 characters.
script.php?module=test.php/././.[...]/././.
In this case, it is necessary to guess so that the entire path string (already cut off) ends with a dot (important!), And not with a slash. To do this, you can add one slash like this:
And one of these options will work for sure.
We analyze
We look in order what transformations will occur with the path
modules/test.php//././.[...]/./././module.class.php
4200 characters
The first thing that happens to the string is that the value from include_path is added to it:
/home/site/public_html/modules/test.php//././.[...]/./././module.class.php
4223 characters
The string is then truncated to MAXPATHLEN (let's say 4096):
/home/site/public_html/modules/test.php//././.[...]/./.
4096 characters
Here you can see why it was necessary to add another slash (otherwise the string would be cut off to a slash). Now this line is normalized, first the extra slashes are removed:
/home/site/public_html/modules/test.php/././.[...]/./.
4095 characters
As a result, we get the right way to the file we need, and this path will already be transferred to the include, and the file we need will be included.
That is, this is how we will include our "test.php" file successfully.
script.php?module=test.php//././.[...]/././.
This means that there is a vulnerability and not a theoretical one. As a result, my client lost a bet, and I won the dispute and 10 rubles for which we bet. Of course, in addition to 10 rubles, I also won trust and respect in the eyes of the client, which is also important.
Notes
Here I will look at a couple of interesting features of the exploitation of this vulnerability.
Exiting the directory
Consider this code:
) ;
Let's skip the point that you can use RFI and include a file with remote server. Let's say "allow_url_include=OFF" on the server.
Consider the situation when we need to include a file from the directory below:
script.php?module=../test.php/././.[...]/././.
Such a call will give an error, such as file not found. And in order to get around this, we need to turn like this:
script.php?module=blabla/../../test.php/././.[...]/././.
It was not in vain that I described about the canonicalization of paths. Thanks to it, the "blabla" directory does not have to exist.
Adding just slashes
An attentive reader probably noticed that in the description of normalization I wrote that they say that extra slashes “/” and dots with slashes “/.” are removed, so why not just use slashes in order to avoid unnecessary crap with a dot at the end.
It's all about algorithms, that is, a slash with a dot "/." is removed completely. But with simple slashes, the situation is a little more complicated, during normalization, every two slashes are replaced by one until one (!) slash remains, example:
/home/site/public_html/modules/test.php//////////////////
57 characters
↓
/home/site/public_html/modules/test.php/////////
48 characters
↓
/home/site/public_html/modules/test.php/////
44 characters
↓
/home/site/public_html/modules/test.php///
42 characters
↓
/home/site/public_html/modules/test.php//
41 characters
↓
/home/site/public_html/modules/test.php/
40 characters
Small digression:
Moreover, if you pay attention to many popular hack resources, you can notice this error. As I understand it, this error began with an article by a certain Raz0r where he proposed a vector:
index.php?act=../../../../../etc/passwd/////[…]/////
And even pay attention to the magazine ][aker repeated this mistake in his article. At the same time, even in the original USH article, it was clearly written that using just slashes is not desirable, and it is necessary that at the end, before normalization, there is a period character. And just slashes (even without a dot at the end) only work in PHP with Suhosin.
That is, use a slash with a dot "/." — more generic method, because, unlike the slashes "/", it works for all versions of php.
Conclusion
I hope this article will help you understand that even the slightest vulnerabilities should not be left in your scripts, since sooner or later you can develop your own attack vector for them, which can lead to serious consequences.
