GHSA-rxp7-9q75-vj3p BIT-openbao-2025-55003 CVE-2025-55003 GO-2025-3856
OpenBao Login MFA Bypass of Rate Limiting and TOTP Token Reuse
- Severity
- 5.7 / 10
- Medium · CVSS 3.1
- Exploit chance (EPSS)
- 0.27%
- Chance of exploitation in the next 30 days. Higher than 18.96% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-307 Improper Restriction of Excessive Authentication Attempts
- Fix
2.3.2- Upgrade github.com/openbao/openbao to this version or later
Description
Impact
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.
Patches
OpenBao v2.3.2 will patch this issue.
Workarounds
Use of rate-limiting quotas can limit an attacker's ability to exploit this: https://openbao.org/api-docs/system/rate-limit-quotas/
References
This issue was disclosed to HashiCorp and is the OpenBao equivalent of the following tickets:
Affected versions
Go
| Package | Vulnerable | Fixed in |
|---|---|---|
| github.com/openbao/openbao | >= 0.1.0, < 2.3.2 |
2.3.2 |
| github.com/openbao/openbao | < 0.0.0-20250807113757-8340a6918f6c |
0.0.0-20250807113757-8340a6918f6c |
| github.com/openbao/openbao | < 0.0.0-20250807113757-8340a6918f6c>= 0.1.0 |
0.0.0-20250807113757-8340a6918f6c |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
github.com/openbao/openbao Go → 2.3.2
- go
go get github.com/openbao/openbao@v2.3.2 && go mod tidy
Severity breakdown
CVSS 3.1 5.7
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Weakness
CWE-307: Improper Restriction of Excessive Authentication Attempts
The product does not implement sufficient measures to prevent multiple failed authentication attempts within a short time frame.
How to prevent it
- Architecture and Design: Common protection mechanisms include: Disconnecting the user after a small number of failed attempts Implementing a timeout Locking out a targeted account Requiring a computational task on the user's part.
- Architecture and Design: Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid [REF-1482]. Consider using libraries with authentication capabilities such as OpenSSL or the ESAPI Authenticator. [REF-45]
References
Advisories
Packages
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-xp3c-3jw3-4vcr OpenBao Skips Stricter Deny Policy for LIST operations | Medium | Also affects github.com/openbao/openbao |
| GHSA-34fc-gh42-pj53 OpenBao's Recovery Mode Vulnerable To Token Leakage via Timing Attack | Critical | Also affects github.com/openbao/openbao |
| GHSA-444v-8vxr-p36h OpenBao Agent Writes Secrets to Stdout | Low | Also affects github.com/openbao/openbao |
| GHSA-59w7-v8rr-pr4p OpenBao's Templated Policies Allow Privilege Escalation via Wildcard Characters | High | Also affects github.com/openbao/openbao |
| GHSA-8w8f-r2xv-4q4j OpenBao: Transit secrets engine crashes on key creation with `derived: true` for asymmetric key types | Medium | Also affects github.com/openbao/openbao |
| GHSA-mwr2-wmgp-crj6 OpenBao's System Backend allows Unauthorized Management of the containing Namespace | Low | Also affects github.com/openbao/openbao |
| GHSA-c36x-h252-g9x2 OpenBao: Cross-namespace lease revocation/renewal via canonical sys/leases/{revoke,renew} — incomplete fix of CVE-2026-45808 | Low | Also affects github.com/openbao/openbao |
| GHSA-6mwx-4547-5vc9 OpenBao: LDAPi ldaputil (wrong escape func) | Medium | Also affects github.com/openbao/openbao |
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