This is a Linkedin shortened URL that seems to be pointing to Linkedin (when you try to reverse it) but in reality, it redirects to this blog post! https://lnkd.in/eSQcwhD
Below we are going to prove that this unvalidated redirect method (OWASP A10) can be used to deceive users and redirect them to malicious websites and malicious executable files by letting them think they are being redirected to Linkedin.
>> Responsible Disclosure: Before I start describing the issue I would like to mention that I followed LinkedIn's policy on reporting vulnerabilities process to the letter (responsible disclosure) and reported the issue exactly as it is described in this page:
After sending a detailed description of the issue (on 27/May/2015), I received the following reply from Linkedin.
Thank you for contacting us and sending us your writeup.
We do perform validation for third-party links that users submit to LinkedIn, checking the destination for inclusion on malware and safe browsing blacklists. The hash you observed is used for that purpose.
Regarding unwinding of our short links or obfuscation, URL encoding is working as expected and the depth of third-party inspectors is not something under our control. Note that some of our redirects use JavaScript, so they may not be capable of analyzing the content. Those redirects also clearly show an interstitial that a redirect is occurring.
If you believe we have misinterpreted your report, please let us know.
Thanks!
[name of responder not being disclosed]
LinkedIn House Security
From my point of view, Linkedin did not understand the extend of the issue I described. So, I replied to that person giving him a couple of examples why I believe this unvalidated redirect "feature" doesn't seem to be working as "expected". Simply because, it can redirect/trick/deceive users into downloading malware and/or visit a malicious website, while under the impression they are being redirected to Linkedin instead. So, my reply to Linkedin response was the following: