Minor corrections/rewrites.
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Revision as of 09:37, 22 March 2014
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== Summary ==
== Summary ==
−
The password change/reset function of an application is a self-service password change/reset mechanism for users. This self-service mechanism allows users to quickly change/reset their password without an administrator intervening. When passwords are changed they are typically changed within the application. When passwords are reset they are either rendered within the application or emailed to the user. This may indicate that the passwords are stored in plaintext.
+
The password change/reset function of an application is a self-service password change/reset mechanism for users. This self-service mechanism allows users to quickly change/reset their password without an administrator intervening. When passwords are changed they are typically changed within the application. When passwords are reset they are either rendered within the application or emailed to the user. This may indicate that the passwords are stored in plaintext
or in a decryptable format
.
== Test objectives ==
== Test objectives ==
Determine the resistance of the application to subversion of the account change process allowing someone to change the password of an account.<br>
Determine the resistance of the application to subversion of the account change process allowing someone to change the password of an account.<br>
−
Determine the resistance of
reset
passwords functionality
to
guessing or bypassing.
+
Determine the resistance of
the
passwords
reset
functionality
against
guessing or bypassing.
== Black Box Testing and Examples ==
== Black Box Testing and Examples ==
For both functionalities (password change and password reset) it is important to check:
For both functionalities (password change and password reset) it is important to check:
−
# if users, other than administrators, can change/reset passwords for accounts other than their own
+
# if users, other than administrators, can change/reset passwords for accounts other than their own
.
−
# if users can manipulate/subvert the password change/reset process to change/reset the password of another user or administrator
+
# if users can manipulate/subvert the password change/reset process to change/reset the password of another user or administrator
.
−
# if the password change/reset process is vulnerable to CSRF
+
# if the password change/reset process is vulnerable to
[[Testing_for_CSRF_(OWASP-SM-005)|
CSRF
]]
=== Test Password Reset ===
=== Test Password Reset ===
−
In addition to the
previus test
it is important to verify:
+
In addition to the
previous checks
it is important to verify
the following
:
* What information is required to reset the password?
* What information is required to reset the password?
The first step is to check whether secret questions/information are required. Sending the password (or a password reset link) to the user email address without first asking for a secret question means relying 100% on the security of that email address, which is not suitable if the application needs a high level of security.<br>
The first step is to check whether secret questions/information are required. Sending the password (or a password reset link) to the user email address without first asking for a secret question means relying 100% on the security of that email address, which is not suitable if the application needs a high level of security.<br>
−
On the other hand, if secret questions are used, the next step is to assess their strength. This specific test is discussed in detail in the [[Testing_for_Weak_security_question/answer_(OTG-AUTHN-008)|Testing for Weak security question/answer]] paragraph of this guide.
<br>
+
On the other hand, if secret questions are used, the next step is to assess their strength. This specific test is discussed in detail in the [[Testing_for_Weak_security_question/answer_(OTG-AUTHN-008)|Testing for Weak security question/answer]] paragraph of this guide.
<br>
<br>
* How are reset passwords communicated to the user?
* How are reset passwords communicated to the user?
The most insecure scenario here is if the password reset tool shows you the password; this gives the attacker the ability to log into the account, and unless the application provides information about the last login the victim would not know that his/her account has been compromised.<br>
The most insecure scenario here is if the password reset tool shows you the password; this gives the attacker the ability to log into the account, and unless the application provides information about the last login the victim would not know that his/her account has been compromised.<br>
A less insecure scenario is if the password reset tool forces the user to immediately change his/her password. While not as stealthy as the first case, it allows the attacker to gain access and locks the real user out.<br>
A less insecure scenario is if the password reset tool forces the user to immediately change his/her password. While not as stealthy as the first case, it allows the attacker to gain access and locks the real user out.<br>
−
The best security is achieved if the password reset is done via an email to the address the user initially registered with, or some other email address; this forces the attacker to not only guess at which email account the password reset was sent to (unless the application
tells that
) but also to compromise that account in order to
take control of
the
victim's access to
the
application
.
<br>
+
The best security is achieved if the password reset is done via an email to the address the user initially registered with, or some other email address; this forces the attacker to not only guess at which email account the password reset was sent to (unless the application
show this information
) but also to compromise that
email
account in order to
obtain
the
temporary password or
the
password reset link
.
<br>
<br>
* Are reset passwords generated randomly or not?
* Are reset passwords generated randomly or not?
−
The most insecure scenario here is if the application sends/visualizes the old password in
cleartext
because
it
means that passwords are not stored in a hashed form, which is a security issue in itself.<br>
+
The most insecure scenario here is if the application sends/visualizes the old password in
clear text
because
this
means that passwords are not stored in a hashed form, which is a security issue in itself.<br>
−
The best security is achieved if passwords are randomly generated with a secure algorithm that
can not
be derived.
<br>
+
The best security is achieved if passwords are randomly generated with a secure algorithm that
cannot
be derived.
<br>
<br>
* Is the reset password functionality requesting confirmation before changing the password?
* Is the reset password functionality requesting confirmation before changing the password?
−
To limit denial-of-service attacks the application should send, via e-mail, a link to the user with a random token, and only if the user visits the link the reset procedure is completed.
So
the current password
should
be valid until
a successful
reset
is complete
.
+
To limit denial-of-service attacks the application should send, via e-mail, a link to the user with a random token, and only if the user visits the link
then
the reset procedure is completed.
This ensures that
the current password
will still
be valid until
the
reset
has been confirmed
.
<br><br>
<br><br>
=== Test Password Change ===
=== Test Password Change ===
−
In addition to the
previus
test it is important to verify:
+
In addition to the
previous
test it is important to verify:
* Is the old password requested to complete the change?
* Is the old password requested to complete the change?
−
The most insecure scenario here is if the application permits the change of the password without requesting the current password
, since
if an attacker is able to take
the
control of a valid session he could easily change the victim's password.<br>
+
The most insecure scenario here is if the application permits the change of the password without requesting the current password
. Indeed
if an attacker is able to take control of a valid session
(s)
he could easily change the victim's password.<br>
See also [[Testing_for_Weak_password_policy_(OWASP-AT-008)|Testing for Weak password policy]] paragraph of this guide.
See also [[Testing_for_Weak_password_policy_(OWASP-AT-008)|Testing for Weak password policy]] paragraph of this guide.