What’s Vulnerable › Vulnerabilities

CVE-2025-55003: OpenBao Login MFA Bypasses Rate Limiting and TOTP Token Reuse

• Severity: medium (CVSS 5.7 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-08-09 · updated 2026-06-17
• Weakness: CWE-307

Description

OpenBao exists to provide a software solution to manage, store, and distribute sensitive data including secrets, certificates, and keys. In versions 2.3.1 and below, OpenBao's Login Multi-Factor Authentication (MFA) system allows enforcing MFA using Time-based One Time Password (TOTP). Due to normalization applied by the underlying TOTP library, codes were accepted which could contain whitespace; this whitespace could bypass internal rate limiting of the MFA method and allow reuse of existing MFA codes. This issue was fixed in version 2.3.2. To work around this, use of rate-limiting quotas can limit an attacker's ability to exploit this: https://openbao.org/api-docs/system/rate-limit-quotas/.

Affected products

• openbao: before 2.3.2 — fixed in 2.3.2

How to fix

Upgrade to a fixed version: openbao 2.3.2. Check the vendor advisory for mitigations.

References

• https://discuss.hashicorp.com/t/hcsec-2025-19-vault-login-mfa-bypass-of-rate-limiting-and-totp-token-reuse/76038
• https://github.com/openbao/openbao/commit/8340a6918f6c41d8f75b6c3845c376d9dc32ed19
• https://github.com/openbao/openbao/security/advisories/GHSA-rxp7-9q75-vj3p

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