CVE-2021-27793
ntermittent authorization failure in aaa tacacs+ with Brocade Fabric OS versions before Brocade...
ntermittent authorization failure in aaa tacacs+ with Brocade Fabric OS versions before Brocade Fabric OS v9.0.1b and after 9.0.0, also in Brocade Fabric OS before Brocade Fabric OS v8.2.3a and after v8.2.0 could cause a user with a valid account to be unable to log into the switch.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- Low
Exploit likelihood
What each source reports
NVD Score used
ntermittent authorization failure in aaa tacacs+ with Brocade Fabric OS versions before Brocade Fabric OS v9.0.1b and after 9.0.0, also in Brocade Fabric OS before Brocade Fabric OS v8.2.3a and after v8.2.0 could cause a user with a valid account to be unable to log into the switch.
- Record
CVE-2021-27793- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:N/I:N/A:P - Weakness
- CWE-863
- Updated
- 2026-11-02
CVE List No score
ntermittent authorization failure in aaa tacacs+ with Brocade Fabric OS versions before Brocade Fabric OS v9.0.1b and after 9.0.0, also in Brocade Fabric OS before Brocade Fabric OS v8.2.3a and after v8.2.0 could cause a user with a valid account to be unable to log into the switch.
- Record
CVE-2021-27793- Updated
- 2026-11-02
EUVDEUVD-2021-14534 No score
ntermittent authorization failure in aaa tacacs+ with Brocade Fabric OS versions before Brocade Fabric OS v9.0.1b and after 9.0.0, also in Brocade Fabric OS before Brocade Fabric OS v8.2.3a and after v8.2.0 could cause a user with a valid account to be unable to log into the switch.
- Record
EUVD-2021-14534- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-j9pj-ff73-q8xm No score
ntermittent authorization failure in aaa tacacs+ with Brocade Fabric OS versions before Brocade...
ntermittent authorization failure in aaa tacacs+ with Brocade Fabric OS versions before Brocade Fabric OS v9.0.1b and after 9.0.0, also in Brocade Fabric OS before Brocade Fabric OS v8.2.3a and after v8.2.0 could cause a user with a valid account to be unable to log into the switch.
- Record
GHSA-j9pj-ff73-q8xm- Weakness
- CWE-863
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, products | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-27793 is a medium vulnerability (CVSS 5.3) in Brocade Fabric Os, published August 12, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.91%, the 60th percentile. No source names a fixed version.