CVE-2021-29437 Account compromise by man-in-the-middle attack
Attackers can hijack user accounts by tricking users into posting login codes, granting full access to user data and actions.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2021-29437?
CVE-2021-29437 is a high-severity authentication bypass vulnerability in ScratchVerifier ScratchOAuth2, published on 13 Apr 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
ScratchOAuth2 is an Oauth implementation for Scratch. Any ScratchOAuth2-related data normally accessible and modifiable by a user can be read and modified by a third party. 1. Scratch user visits 3rd party site. 2. 3rd party site asks user for Scratch username. 3. 3rd party site pretends to be user and gets login code from ScratchOAuth2. 4. 3rd party site gives code to user and instructs them to post it on their profile. 5. User posts code on their profile, not knowing it is a ScratchOAuth2 login code. 6. 3rd party site completes login with ScratchOAuth2. 7. 3rd party site has full access to anything the user could do if they directly logged in. See referenced GitHub security advisory for patch notes and workarounds.
Weakness: CWE-863
Which versions are affected by CVE-2021-29437?
It affects 1 product.
Products include Scratchoauth2 Project Scratchoauth2.
How do I fix CVE-2021-29437?
No fix has been published for CVE-2021-29437 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2021-29437 being exploited?
There is no known exploitation of CVE-2021-29437 in the wild and no public exploit code.
Other vulnerabilities in ScratchVerifier ScratchOAuth2
Sources
Also known as GHSA-gvpg-23fh-8g75.