TOTP token timing side-channel
Published May 20, 2022 · Updated Apr 23, 2025
Observable timing discrepancy in Constantoine totp-rs before 1.1.0 allows remote authenticated users to guess TOTP tokens via repeated verification requests. The TOTP::check function compares candidate tokens with an ordinary non-constant-time operation, leaking timing differences that reveal matching digits. The attacker must already know the account password and make high-complexity, interactive network requests; a recovered token can be reused within the same time window for authentication.
Summary
What happened
Observable timing discrepancy in Constantoine totp-rs before 1.1.0 allows remote authenticated users to guess TOTP tokens via repeated verification requests. The TOTP::check function compares candidate tokens with an ordinary non-constant-time operation, leaking timing differences that reveal matching digits. The attacker must already know the account password and make high-complexity, interactive network requests; a recovered token can be reused within the same time window for authentication.
The record
- CVE
- CVE-2022-29185
- Published
- May 20, 2022
- Updated
- Apr 23, 2025
- Vendor
- Constantoine
- Product
- totp-rs
- Classifications
- CWE-203, CWE-208
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- May 20, 2022CVE publishedPublication date reported by the CVE source.
- Apr 23, 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?
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- Affected versionversion=<1.1.0
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.
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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