Did you ever wonder, when you click on a particular website a different website opens? Do you know what we call it? Do you know the impact of it?
Here’s a blog which alerts you the harm of such activity.
Open Redirection Vulnerability
An Open Redirection is when a web application or server uses a user-submitted link to redirect the user to a given website or page. Even though it seems like a harmless action, to let a user decide on which page he wants to be redirected to if exploited such technique can have a serious impact especially when combined with other vulnerabilities and tricks.
How can An Open Redirect Web Vulnerability be exploited?
Abusing the Trust Users Have in the Vulnerable Website
Since the domain name in a URL is the only indicator for a user to recognize a legitimate website from a non-legitimate one, an attacker can abuse this trust to exploit an open redirect vulnerability on the vulnerable website, and redirect the user to a malicious page to execute further attacks.
Exploiting an Open Redirect Vulnerability for a Phishing Attack
When the user clicks on a link of a legitimate website he often won’t be suspicious if suddenly a login prompt shows up. To launch a successful phishing attack the attacker sends the victim a link, for example via email, which exploits the vulnerability on the vulnerable
By exploiting the open redirect vulnerability on the legitimate website, the attacker is redirecting the victim to,
Which is a phishing page that is similar to the legit website. Once the visitor is on the attacker’s malicious website, he enters his credentials on the login form which points to a script that is controlled by the attacker. The script is typically used to save the username and the password that is being typed in by the victim, which attackers typically use at a later stage to impersonate the victim on the legitimate website.
The probability of a successful phishing attack is quite high since the domain example.com is shown when the user clicks on the link.
Exploiting an Open Redirect Vulnerability to Redirect Victims to Malicious Websites
It is also possible to redirect an otherwise careful internet user to a site hosting attacker-controlled content, like a browser exploit or a page executing a CSRF attack. As above, the chances that the victim clicks the link are higher if the site the link points to is trusted by the victim.
Impact of an Open Redirection Vulnerability
The impacts can be many, and vary from theft of information and credentials, to the redirection to malicious websites containing attacker-controlled content, which in some cases even cause XSS attacks. So even though an open redirection might sound harmless at first, the impacts of it can be severe.
Preventing Open Redirection Vulnerabilities
The easiest and most effective way to prevent vulnerable open redirects would be to not let the user control where your page redirects him to. If you have to redirect the user based on URLs, you should always use an ID which is internally resolved to the respective URL. If you want the user to be able to issue redirects you should use a redirection page that requires the user to click on the link instead of just redirecting them. You should also check that the URL begins with http:// or https:// and also invalidate all other URLs to prevent the use of malicious URI’s(Uniform Resource Identifier).