Account compromise via unlabeled verification codes
Published Apr 13, 2021 · Updated Aug 3, 2024
Incorrect authorization in ScratchOAuth2 before 9220c2a allows remote attackers to read and modify a victim's OAuth-accessible data. The gen_code flow renders a bare verification code, and the login endpoint accepts it after a third-party site requests it for the victim's username. Exploitation requires the victim to visit the attacker's site and post the supplied code on a Scratch profile, after which the attacker gains the same read and write access as that user.
Summary
What happened
Incorrect authorization in ScratchOAuth2 before 9220c2a allows remote attackers to read and modify a victim's OAuth-accessible data. The gen_code flow renders a bare verification code, and the login endpoint accepts it after a third-party site requests it for the victim's username. Exploitation requires the victim to visit the attacker's site and post the supplied code on a Scratch profile, after which the attacker gains the same read and write access as that user.
The record
- CVE
- CVE-2021-29437
- Published
- Apr 13, 2021
- Updated
- Aug 3, 2024
- Vendor
- ScratchVerifier
- Product
- ScratchOAuth2
- Classifications
- CWE-863, T1566
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 13, 2021CVE publishedPublication date reported by the CVE source.
- Aug 3, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 9220c2a
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
- ScratchOAuth2 victim-assisted login-code procedurefunctional · demonstrated
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Technologies
Your stack
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Your stack
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