The Hacker News - Most Trusted Cyber Security and Computer Security Analysis: Bypassing OAuth

It's no secret that 3rd party apps can boost productivity, enable remote and hybrid work and are overall, essential in building and scaling a company's work processes.  An innocuous process much like clicking on an attachment was in the earlier days of email, people don't think twice when connecting an app they need with their Google workspace or M365 environment, etc. Simple actions that users take, from creating an email to updating a contact in the CRM, can result in several other automatic actions and notifications in the connected platforms.  As seen in the image below, the OAuth mechanism makes it incredibly easy to interconnect apps and many don't consider what the possible ramifications could be. When these apps and other add-ons for SaaS platforms ask for permissions' access, they are usually granted without a second thought, presenting more opportunities for bad actors to gain access to a company's data. This puts companies at risk for supply chain

Google last month addressed a high-severity flaw in its OAuth client library for Java that could be abused by a malicious actor with a compromised token to deploy arbitrary payloads. Tracked as  CVE-2021-22573 , the vulnerability is rated 8.7 out of 10 for severity and relates to an authentication bypass in the library that stems from an improper verification of the cryptographic signature. Credited with discovering and reporting the flaw on March 12 is  Tamjid Al Rahat , a fourth-year Ph.D. student of Computer Science at the University of Virginia, who has been awarded $5,000 as part of Google's bug bounty program. "The vulnerability is that the IDToken verifier does not verify if the token is properly signed," an  advisory  for the flaw reads. "Signature verification makes sure that the token's payload comes from a valid provider, not from someone else. An attacker can provide a compromised token with custom payload. The token will pass the validation on

Facebook OAuth is used to communicate between Applications & Facebook users, to grant additional permissions to your favorite apps. To make this possible, users have to ' allow or accept ' the application request so that app can access your account information with required permissions. As a normal Facebook user we always think that it is better than entering your Facebook credentials, we can  just allow specific permissions to an app in order to make it work with your account. Today whitehat Hacker ' Nir Goldshlager ' reported ' The Hacker News ' that he discovered a very critical vulnerability in Facebook's OAuth system, that allowed him to get full control over any Facebook account easily even without ' allow or accept ' options. For this purpose he hunt the flaw in a very mannered way i.e Step 1) Understanding the OAuth URL Step 2) Finding a way to use custom parameters in URL Step 3) Bypassing OAuth ' Allow '