How severe is CVE-2021-27793?

CVE-2021-27793 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.

Is CVE-2021-27793 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (55th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-27793?

CVE-2021-27793 primarily affects Broadcom Fabric Operating System. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-27793?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-27793 published?

CVE-2021-27793 was published on 2021-08-12 and last updated on 2026-06-17.

CVE-2021-27793

CVE-2021-27793 is a medium-severity vulnerability in Broadcom Fabric Operating System with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-863.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
CVSS v2: 5.0
EPSS exploit prediction: 1% (55th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-863
Affected product: Broadcom Fabric Operating System
Published: 2021-08-12
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2021-27793?: 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.
How severe is CVE-2021-27793?: CVE-2021-27793 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.
Is CVE-2021-27793 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (55th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-27793?: CVE-2021-27793 primarily affects Broadcom Fabric Operating System. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-27793?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-27793 published?: CVE-2021-27793 was published on 2021-08-12 and last updated on 2026-06-17.

References

Affected products (4)

cpe:2.3:o:broadcom:fabric_operating_system:*:*:*:*:*:*:*:*
cpe:2.3:o:broadcom:fabric_operating_system:8.2.3:*:*:*:*:*:*:*
cpe:2.3:o:broadcom:fabric_operating_system:9.0.1:*:*:*:*:*:*:*
cpe:2.3:o:broadcom:fabric_operating_system:9.0.1a:*:*:*:*:*:*:*

More vulnerabilities in Broadcom Fabric Operating System

CVE-2022-33186 — Critical (CVSS 9.8): A vulnerability in Brocade Fabric OS software v9.1.1, v9.0.1e, v8.2.3c, v7.4.2j, and earlier versions could allow a…
CVE-2021-27797 — Critical (CVSS 9.8): Brocade Fabric OS before Brocade Fabric OS v8.2.1c, v8.1.2h, and all versions of Brocade Fabric OS v8.0.x and v7.x…
CVE-2020-15374 — Critical (CVSS 9.8): Rest API in Brocade Fabric OS v8.2.1 through v8.2.1d, and 8.2.2 versions before v8.2.2c is vulnerable to multiple…
CVE-2020-15373 — Critical (CVSS 9.8): Multiple buffer overflow vulnerabilities in REST API in Brocade Fabric OS versions v8.2.1 through v8.2.1d, and 8.2.2…
CVE-2020-15371 — Critical (CVSS 9.8): Brocade Fabric OS versions before Brocade Fabric OS v9.0.0, v8.2.2c, v8.2.1e, v8.1.2k, v8.2.0_CBN3, contains code…
CVE-2019-18805 — Critical (CVSS 9.8): An issue was discovered in net/ipv4/sysctl_net_ipv4.c in the Linux kernel before 5.0.11. There is a…

All CVEs affecting Broadcom Fabric Operating System →

Other CWE-863 (Incorrect Authorization) vulnerabilities

CVE-2026-48286 — Critical (CVSS 10.0): Adobe Campaign Classic (ACC) versions 7.4.3 build 9396 and earlier are affected by an Incorrect Authorization…
CVE-2026-48303 — Critical (CVSS 10.0): Adobe Campaign Classic (ACC) versions 7.4.3 build 9394 and earlier are affected by an Incorrect Authorization…
CVE-2026-44330 — Critical (CVSS 10.0): free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's NEF mounts the…
CVE-2026-46595 — Critical (CVSS 10.0): Previously, CVE-2024-45337 fixed an authorization bypass for misused ssh server configurations; if any other type of…
CVE-2026-33105 — Critical (CVSS 10.0): Improper authorization in Microsoft Azure Kubernetes Service allows an unauthorized attacker to elevate privileges over…
CVE-2026-32213 — Critical (CVSS 10.0): Improper authorization in Azure AI Foundry allows an unauthorized attacker to elevate privileges over a network.

Browse all CWE-863 (Incorrect Authorization) vulnerabilities →