Account forgery via skipped ID-token signature check
Published May 3, 2022 · Updated Apr 21, 2025
Authentication bypass in Google OAuth Client Library for Java before 1.33.3 lets remote authenticated users pass forged ID tokens to applications. The IdTokenVerifier verify method checks claims without first validating the token signature, so altered email, phone, or identity fields are accepted. Exploitation requires an application to trust the verifier result; downstream services that recheck signatures are not affected.
Summary
What happened
Authentication bypass in Google OAuth Client Library for Java before 1.33.3 lets remote authenticated users pass forged ID tokens to applications. The IdTokenVerifier verify method checks claims without first validating the token signature, so altered email, phone, or identity fields are accepted. Exploitation requires an application to trust the verifier result; downstream services that recheck signatures are not affected.
The record
- CVE
- CVE-2021-22573
- Published
- May 3, 2022
- Updated
- Apr 21, 2025
- Vendor
- Product
- Google OAuth Client Library for Java
- Classifications
- CWE-347, T1606
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- May 3, 2022CVE publishedPublication date reported by the CVE source.
- Apr 21, 2025Record 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=unspecified <1.33.2
What conditions does exploitation require?
What is affected?
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.
Weakness, pattern, technique
Public exploit references
- Malformed ID token signature proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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