Difference between revisions of "AppSensor DetectionPoints"

RE1

Unexpected HTTP Commands

RequestException

An HTTP request is received which contains unexpected commands. A list of accepted commands should be generated (i.e. GET and POST) and all other HTTP commands should generate an event.

Instead of a GET or POST request, the user sends a TRACE request to the application.

[Java] [.Net] [PHP]

RE2

Attempts To Invoke Unsupported HTTP Methods

RequestException

An http request is received which contains a non-existent HTTP command

Instead of a GET or POST request, the user sends a TEST request to the application (TEST is not a valid http request)

[Java] [.Net] [PHP]

RE3

GET When Expecting POST

RequestException

A page which is expecting only GET requests, receives a POST.

The user sends a GET request to a page which has only been used for POSTs

[Java] [.Net] [PHP]

RE4

POST When Expecting GET

RequestException

A page which is expecting only POST requests, receives a GET

The user uses a proxy tool to build a custom POST request and sends it to a page which has been accessed by GET requests.

[Java] [.Net] [PHP]

AE1

Use Of Multiple Usernames

AuthenticationException

Multiple usernames are attempted when logging into the application. The assignment of login attempts to a user can be based off of a sessionID given to the user when they visit the website. Correlating based on IP address is difficult since multiple users could be using the site from the same IP address (e.g. corporate NAT)

User first tries username bob, then username sue, then steve etc

[Java] [.Net] [PHP]

AE2

Multiple Failed Passwords

AuthenticationException

For a single username, multiple bad passwords are entered

User tries username:password combination of user:pass1, user:pass2, user:pass3, etc

[Java] [.Net] [PHP]

AE3

High Rate Of Login Attempts

AuthenticationException

The number of logins sent per minute becomes too high indicating an automated login attack

User sends the following login attempts within 1 second. user1:pass1, user1:pass2, user2:pass3, user2:pass4

[Java] [.Net] [PHP]

AE4

Unexpected Quantity Of Characters In Username

AuthenticationException

The user provides a username with a large number of characters

The user sends a username that is 200 characters long

[Java] [.Net] [PHP]

AE5

Unexpected Quantity Of Characters In Password

AuthenticationException

The user provides a password with a large number of characters

The user sends a password that is 200 characters long

[Java] [.Net] [PHP]

AE6

Unexpected Types Of Characters In Username

AuthenticationException

The user provides non-printable characters such as the null byte. Any characters below hex value 20 or above 7E are considered illegal (decimal values of below 32 or above 126)

The user sends a username that contains ascii characters below 20 or above 7E

[Java] [.Net] [PHP]

AE7

Unexpected Types Of Characters In Password

AuthenticationException

The user provides characters such as the null byte, alt-characters, (WHAT IS THE NAME FOR THOSE)

The user sends a password that contains ascii characters below 20 or above 7E

[Java] [.Net] [PHP]

AE8

Providing Only The Username

AuthenticationException

The user submits a post request which only contains the username variable. The password variable has been removed. This is different from only providing the username in the login form since in that case the password variable would be present and empty.

The user uses a proxy tool to remove the password variable from the submitted post request.

[Java] [.Net] [PHP]

AE9

Providing Only The Password

AuthenticationException

The user submits a post request which only contains the password variable. The username variable has been removed. This is different from only providing the password in the login form since in that case the username variable would be present and empty.

The user uses a proxy tool to remove the username variable from the submitted post request.

[Java] [.Net] [PHP]

AE10

Adding Additional POST Variables

AuthenticationException

Additional, unexpected post variables are received during an authentication request.

The user uses a proxy tool to add the additional post variable of admin=true to the post request

[Java] [.Net] [PHP]

AE11

Removing POST Variables

AuthenticationException

Expected post variables are not present within the submitted authentication requests

The user uses a proxy tool to remove an additional post variable, such as guest=true, from the post request

[Java] [.Net] [PHP]

SE1

Modifying Existing Cookies

SessionException

A request is received containing a cookie with a modified value. This could be determined if the cookie is modified to an illegal value.

The user uses a proxy tool to change the encrypted cookie to an alternative value which does not properly decode within the application. Or, the user modifies an unencrypted cookie and sets an illegal value for a particular variable.

[Java] [.Net] [PHP]

SE2

Adding New Cookies

SessionException

A request is received which contains additional cookies that are not expected by the application.

The user uses a proxy tool to add additional cookies to the request.

[Java] [.Net] [PHP]

SE3

Deleting Existing Cookies

SessionException

A request is received which does not contain the expected cookies.

The user uses a proxy tool to remove cookies or portions of cookies from a request.

[Java] [.Net] [PHP]

SE4

Substituting Another User's Valid Session ID Or Cookie

SessionException

A request is received which contains cookie data that is clearly from another user or another session.

The user uses a proxy tool to substitute valid data from another user or session into the cookie. An example would be changing some sort of identification number within the cookie.

[Java] [.Net] [PHP]

SE5

Source IP Address Changes During Session

SessionException

Valid requests, containing valid session credentials, are received from multiple source IP addresses.

User A's session is compromised and User B begins using the account. The requests originating from User B will possibly contain a different source IP address the User A. The source IP addresses could be the same if both users where behind the same NAT.

[Java] [.Net] [PHP]

SE6

Change Of User Agent Mid Session

SessionException

The User-Agent value of the header changes during an authenticated session. This indicates a different browser is now being used. Although this value is under the control of the sender, a change in this may indicates that the session has been compromised and is being used another individual. This will likely not be the case that the user has simply copied and pasted the URL from one browser to another on the same system because this action would not copy over the appropriate session identifiers.

Midsession, the UserAgent changes from Firefox to Internet Explorer

[Java] [.Net] [PHP]

ACE1

Modifying URL Arguments Within a GET For Direct Object Access Attempts

AccessControlException

The application is designed to use an identifier for a particular object, such as using categoryID=4 or user=guest within the URL. A user modifies this value in an attempt to access unauthorized information. This exception should be thrown anytime the identifier received from the user is not authorized due to the identifier being nonexistent or the identifier not authorized for that user.

The user modifies the following URL from FIX THIS

[Java] [.Net] [PHP]

ACE2

Modifying Parameters Within A POST For Direct Object Access Attempts

AccessControlException

The value of a non-free text html form element (i.e. drop down box, radio button) is modified to an illegal value. The value either does not exist or is not authorized for the user.

The user uses a proxy tool to intercept a post request and changes the posted value to a value that was not available through the normal display. For example, the user encounters a dropdown box containing the numbers 1 through 10. The user selects 5 and then intercepts the post to change the submitted value to 100.

[Java] [.Net] [PHP]

ACE3

Force Browsing Attempts

AccessControlException

An authenticated user sends a request for a non-existent page or a page that is not authorized for the user.

The user is authenticated and requests site.com/PageThatDoesNotExist

[Java] [.Net] [PHP]

ACE4

Evading Presentation Access Control Through Custom Posts

AccessControlException

A post request is received which is not authorized for the current user and the user could not have performed this action without crafting a custom POST request. This situation is most likely to occur when presentation layer access controls are in place and have removed the user's ability to initiate the action through the presentation of the application. An attacker may be aware of the functionality and attempt to bypass this presentation layer access control by crafting their own custom message and sending this in an attempt to execute the functionality.

The application contains the ability for an administrator to delete a user. This method is normally invoked by entering the username and posting to https://oursite/deleteuser Presentation layer access controls ensure the delete user form is not displayed to non-administrator users. A malicious user has access to a non-administrator account and is aware of the delete user functionality. The malicious user sends a custom crafted post message to https://oursite/deleteuser in an attempt to execute the delete user method.

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IE1

Cross Site Scripting Attempt

InputException

The HTTP request contains common XSS attacks which are often used by attackers probing for XSS vulnerabilities. Detection should be configured to test all GET and POST values as well as all header names and values for the following values.

The user uses a proxy tool to add an XSS attack to the header value and the """"displayname"""" post variable. The header value could be displayed to an admin viewing log files and the """"displayname"""" post variable may be stored in the application and displayed to other users. Note, the following xss attacks would be used by an attacker to probe for vulnerability. An actual XSS attack would be customized by the attacker.

<script>alert(document.cookie);</script> <script>alert();</script> alert(String.fromCharCode(88,83,83)) <IMG SRC="javascript:alert('XSS');"> <IMG SRC=javascript:alert('XSS')> <IMG SRC=javascript:alert(&quot;XSS&quot;)> <BODY ONLOAD=alert('XSS')>

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IE2

Violations Of Implemented White Lists

InputException

The application receives user-supplied data that violates an established white list validation.

The user submits data that is not correct for the particular field. This may not be attack data necessarily, but repeated violations could be an attempt by the attacker to determine how an application works or to discover a flaw.

[Java] [.Net] [PHP]

EE1

Double Encoded Characters

EncodingException

An HTTP request is received which contains values that have been double encoded.

The user sends encodes the % symbol to %25 and appends 3C. The user is sending %253C which may be interpreted by the application as %3C which is actually <.

[Java] [.Net] [PHP]

EE2

Unexpected Encoding Used

EncodingException

An HTTP request is received which contains values that have encoded in an unexpected format.

The user encodes an attack such as alert(document.cookie) into the UTF-7 format and sends this data the application. This could bypass validation filters and be rendered to a user in certain situations.

[Java] [.Net] [PHP]

CIE1

Blacklist Inspection For Common SQL Injection Values

CommandInjectionException

A request is received which contains common SQL injection attack attempts. The point of this detection is not to detect all variations of a SQL injection attack, but to detect the common probes which an attacker or tool might use to determine if a SQL injection vulnerability is present. Unless the site contains some sort of message board for discussing SQL injection, there is little reason that the SQL injection examples should ever be received from a user request.

The user sends a request and modifies a URL parameter from category = 5 to category = 5' OR '1' = '1 in an attempt to perform an SQL injection attack. The user could perform similar attacks by modifying post variables or even the request headers to contain SQL injection attacks. ' OR '1'='1 ' OR 'a'='a ' OR 1=1-- xp_cmdshell UNION JOIN

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CIE2

Detect Abnormal Quantity Of Returned Records

CommandInjectionException

A database query is executed which returns more records than expected. For example, if the query should only return 1 record and 100 records are returned, then something has likely gone wrong.

The application is designed to allow a user to maintain 5 profiles. A user makes a request to view all of their profiles. The database query, which is expected to always return 5 or less results, returns 10,000 records. Something in the application, or user's actions, has caused unauthorized data to be returned.

[Java] [.Net] [PHP]

CIE3

Null Byte Character In File Request

CommandInjectionException

A request is received to download a file from the server. The filename requested contains the null byte the file name. This is an attempted OS injection attack.

The user modifies the filename of the requested file to download to contain the null byte. The null byte can be added by inserting the hex value %00.

[Java] [.Net] [PHP]

CIE4

Carriage Return Or Line Feed Character In File Request

CommandInjectionException

A request is received which contains the carriage return or line feed characters within the posted data or the URL parameters. This is an attempted HTTP split response attack.

The user includes the hex value %0D or %0A in the http request post data or URL parameters.

[Java] [.Net] [PHP]

FIO1

Detect Large Individual Files

FileIOException

A file upload feature detects that a large file has been submitted for upload which exceeds the maximum upload size

The user attempts to upload a large file to occupy resources or fill up disk space

[Java] [.Net] [PHP]

FIO2

Detect Large Number Of File Uploads

FileIOException

A user uploads an excessively large number of files.

A single user attempts to upload multiple small files to occupy resources or fill up disk space

[Java] [.Net] [PHP]

UT1

Irregular Use Of Application

UserTrendException

The application receives numerous requests for the same page or feature from a user. The user may be sending different data combinations or trying to detect errors in the page.

The user requests a particular page, such as the address update page, numerous times.

[Java] [.Net] [PHP]

UT2

Speed Of Application Use

UserTrendException

The speed of requests from a user indicates that an automated tool is being used to access the site. The use of a tool may indicate reconnaissance for an attack or attempts to identify vulnerabilities in the site.

The user utilizes an automated tool to request hundreds of pages per minute.

[Java] [.Net] [PHP]

UT3

Frequency Of Site Use

UserTrendException

Does the user normally access the site 1 per week, and this is now many times per day

[Java] [.Net] [PHP]

UT4

Frequency Of Feature Use

UserTrendException

The rate of a user utilizing a particular application feature changes dramatically.

[Java] [.Net] [PHP]

STE1

High Number Of Logouts Across The Site

SystemTrendException

A sudden spike in logouts across the application could indicate a XSS and CSRF attack placed within the application which is automatically logging off users.

The hourly usage of the logoff feature of the application suddenly spikes by 500%.

[Java] [.Net] [PHP]

STE2

High Number Of Logins Across The Site

SystemTrendException

A sudden spike in logins across the application could indicate users being redirected to the site from a phishing email looking to exploit a XSS vulnerability in the site.

The hourly usage of the logon feature of the application suddenly spikes by 500%.

[Java] [.Net] [PHP]

STE3

High Number Of Same Transaction Across The Site

SystemTrendException

A sudden spike in similar activity across numerous users of the application may indicate a phishing attack or CSRF attack against the users.

The hourly usage of the update email address feature of the application suddenly spikes by 500%.

[Java] [.Net] [PHP]