Vulnerability Details : CVE-2021-29437
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.
Products affected by CVE-2021-29437
- cpe:2.3:a:scratchoauth2_project:scratchoauth2:*:*:*:*:*:scratch:*:*
Exploit prediction scoring system (EPSS) score for CVE-2021-29437
0.27%
Probability of exploitation activity in the next 30 days
EPSS Score History
~ 48 %
Percentile, the proportion of vulnerabilities that are scored at or less
CVSS scores for CVE-2021-29437
Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Score Source | First Seen |
---|---|---|---|---|---|---|
4.0
|
MEDIUM | AV:N/AC:H/Au:N/C:P/I:P/A:N |
4.9
|
4.9
|
NIST | |
6.8
|
MEDIUM | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N |
1.6
|
5.2
|
NIST | |
8.0
|
HIGH | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N |
1.6
|
5.8
|
GitHub, Inc. |
CWE ids for CVE-2021-29437
-
The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.Assigned by: security-advisories@github.com (Secondary)
References for CVE-2021-29437
-
https://github.com/ScratchVerifier/ScratchOAuth2/commit/9220c2a77eda3df37a84486ad722f1ad0985d8e7
SECURITY: Mitigate MITM (GHSA-gvpg-23fh-8g75) · ScratchVerifier/ScratchOAuth2@9220c2a · GitHubPatch
-
https://github.com/ScratchVerifier/ScratchOAuth2/security/advisories/GHSA-gvpg-23fh-8g75
Account compromise by man-in-the-middle attack · Advisory · ScratchVerifier/ScratchOAuth2 · GitHubPatch;Third Party Advisory
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