GHSA-2q8q-8fgw-9p6p BIT-openbao-2025-55001 CVE-2025-55001 GO-2025-3859
OpenBao LDAP MFA Enforcement Bypass When Using Username As Alias
- Severity
- 6.5 / 10
- Medium · CVSS 3.1
- Exploit chance (EPSS)
- 0.24%
- Chance of exploitation in the next 30 days. Higher than 15.66% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-156 Improper Neutralization of Whitespace
- Fix
2.3.2- Upgrade github.com/openbao/openbao to this version or later
Description
Impact
OpenBao allows assignment of policies and MFA attribution based upon entity aliases, chosen by the underlying auth method. When using the username_as_alias=true parameter in the LDAP auth method, the caller-supplied username is used verbatim without normalization, allowing an attacker to bypass alias-specific MFA requirements.
Patches
OpenBao v2.3.2 will patch this issue.
Workarounds
LDAP methods are only vulnerable if using username_as_alias=true. Remove all usage of this parameter and update any entity aliases accordingly.
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 | < 0.0.0-20250807212521-c52795c1ef74 |
0.0.0-20250807212521-c52795c1ef74 |
| github.com/openbao/openbao | < 0.0.0-20250807212521-c52795c1ef74>= 0.1.0 |
0.0.0-20250807212521-c52795c1ef74 |
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 6.5
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- High
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Weakness
CWE-156: Improper Neutralization of Whitespace
The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could be interpreted as whitespace when they are sent to a downstream component.
How to prevent it
- Developers should anticipate that whitespace will be injected/removed/manipulated in the input vectors of their product. Use an appropriate combination of denylists and allowlists to ensure only valid, expected and appropriate input is processed by the system.
- Implementation: Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue." Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
- Implementation: While it is risky to use dynamically-generated query strings, code, or commands that mix control and data together, sometimes it may be unavoidable. Properly quote arguments and escape any special characters within those arguments. The most conservative approach is to escape or filter all characters that do not pass an extremely strict allowlist (such as everything that is not alphanumeric or white space). If some special characters are still needed, such as white space, wrap each argument in quotes after the escaping/filtering step. Be careful of argument injection (CWE-88).
- Implementation: Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.
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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