CVE-2021-3956
A read-only authentication bypass vulnerability was reported in the Third Quarter 2021 release of...
A read-only authentication bypass vulnerability was reported in the Third Quarter 2021 release of Lenovo XClarity Controller (XCC) firmware affecting XCC devices configured in LDAP Authentication Only Mode and using an LDAP server that supports “unauthenticated bind”, such as Microsoft Active Directory. An unauthenticated user can gain read-only access to XCC in such a configuration, thereby allowing the XCC device configuration to be viewed but not changed. XCC devices configured to use local authentication, LDAP Authentication + Authorization Mode, or LDAP servers that support only “authenticated bind” and/or “anonymous bind” are not affected.
Attack profile
How easy it is to exploit
- Attack vector
- Adjacent network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
A read-only authentication bypass vulnerability was reported in the Third Quarter 2021 release of Lenovo XClarity Controller (XCC) firmware affecting XCC devices configured in LDAP Authentication Only Mode and using an LDAP server that supports “unauthenticated bind”, such as Microsoft Active Directory. An unauthenticated user can gain read-only access to XCC in such a configuration, thereby allowing the XCC device configuration to be viewed but not changed. XCC devices configured to use local authentication, LDAP Authentication + Authorization Mode, or LDAP servers that support only “authenticated bind” and/or “anonymous bind” are not affected.
- Record
CVE-2021-3956- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - Weakness
- CWE-863
- Updated
- 2026-11-02
EUVDEUVD-2021-27165
A read-only authentication bypass vulnerability was reported in the Third Quarter 2021 release of Lenovo XClarity Controller (XCC) firmware affecting XCC devices configured in LDAP Authentication Only Mode and using an LDAP server that supports “unauthenticated bind”, such as Microsoft Active Directory. An unauthenticated user can gain read-only access to XCC in such a configuration, thereby allowing the XCC device configuration to be viewed but not changed. XCC devices configured to use local authentication, LDAP Authentication + Authorization Mode, or LDAP servers that support only “authenticated bind” and/or “anonymous bind” are not affected.
- Record
EUVD-2021-27165- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-fjvh-mchr-664c
A read-only authentication bypass vulnerability was reported in the Third Quarter 2021 release of...
A read-only authentication bypass vulnerability was reported in the Third Quarter 2021 release of Lenovo XClarity Controller (XCC) firmware affecting XCC devices configured in LDAP Authentication Only Mode and using an LDAP server that supports “unauthenticated bind”, such as Microsoft Active Directory. An unauthenticated user can gain read-only access to XCC in such a configuration, thereby allowing the XCC device configuration to be viewed but not changed. XCC devices configured to use local authentication, LDAP Authentication + Authorization Mode, or LDAP servers that support only “authenticated bind” and/or “anonymous bind” are not affected.
- Record
GHSA-fjvh-mchr-664c- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - Weakness
- CWE-863
- Updated
- 2026-11-02
NVD
A read-only authentication bypass vulnerability was reported in the Third Quarter 2021 release of Lenovo XClarity Controller (XCC) firmware affecting XCC devices configured in LDAP Authentication Only Mode and using an LDAP server that supports “unauthenticated bind”, such as Microsoft Active Directory. An unauthenticated user can gain read-only access to XCC in such a configuration, thereby allowing the XCC device configuration to be viewed but not changed. XCC devices configured to use local authentication, LDAP Authentication + Authorization Mode, or LDAP servers that support only “authenticated bind” and/or “anonymous bind” are not affected.
- Record
CVE-2021-3956- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - CVSS 2.0
- 4.3 Medium
AV:N/AC:M/Au:N/C:P/I:N/A:N - Weakness
- CWE-863
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-3956 is a medium vulnerability (CVSS 4.3) in Lenovo Xclarity Controller (xcc), published May 18, 2022. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.79%, the 56th percentile. No source names a fixed version.