How severe is CVE-2021-27791?

CVE-2021-27791 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2021-27791 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (45th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-27791?

CVE-2021-27791 affects Broadcom Fabric Operating System. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-27791?

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

When was CVE-2021-27791 published?

CVE-2021-27791 was published on 2021-08-12 and last updated on 2026-06-17.

CVE-2021-27791

CVE-2021-27791 is a medium-severity vulnerability in Broadcom Fabric Operating System with a CVSS 3.x base score of 5.4. 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-125.

Key facts

Severity: Medium (CVSS 3.x base score 5.4)
CVSS v2: 5.5
EPSS exploit prediction: 1% (45th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-125
Affected product: Broadcom Fabric Operating System
Published: 2021-08-12
Last modified: 2026-06-17

Description

The function that is used to parse the Authentication header in Brocade Fabric OS Web application service before Brocade Fabric OS v9.0.1a and v8.2.3a fails to properly process a malformed authentication header from the client, resulting in reading memory addresses outside the intended range. An unauthenticated attacker could discover a request, which could bypass the authentication process.

Frequently asked questions

What is CVE-2021-27791?: The function that is used to parse the Authentication header in Brocade Fabric OS Web application service before Brocade Fabric OS v9.0.1a and v8.2.3a fails to properly process a malformed authentication header from the client, resulting in reading memory addresses outside the intended range. An unauthenticated attacker could discover a request, which could bypass the authentication process.
How severe is CVE-2021-27791?: CVE-2021-27791 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2021-27791 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (45th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-27791?: CVE-2021-27791 affects Broadcom Fabric Operating System. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-27791?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-27791 published?: CVE-2021-27791 was published on 2021-08-12 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:broadcom:fabric_operating_system:*:*:*:*:*:*:*:*

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