How severe is CVE-2021-41025?

CVE-2021-41025 has a CVSS 3.x base score of 7.3, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.

Is CVE-2021-41025 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (70th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-41025?

CVE-2021-41025 primarily affects Fortinet Fortiweb. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-41025?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-41025 published?

CVE-2021-41025 was published on 2021-12-08 and last updated on 2026-06-17.

CVE-2021-41025

CVE-2021-41025 is a high-severity vulnerability in Fortinet Fortiweb with a CVSS 3.x base score of 7.3. 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-362.

Key facts

Severity: High (CVSS 3.x base score 7.3)
CVSS v2: 7.5
EPSS exploit prediction: 1% (70th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-362
Affected product: Fortinet Fortiweb
Published: 2021-12-08
Last modified: 2026-06-17

Description

Multiple vulnerabilities in the authentication mechanism of confd in FortiWeb versions 6.4.1, 6.4.0, 6.3.0 through 6.3.15, 6.2.0 through 6.2.6, 6.1.0 through 6.1.2, 6.0.0 thorugh 6.0.7, including an instance of concurrent execution using shared resource with improper synchronization and one of authentication bypass by capture-replay, may allow a remote unauthenticated attacker to circumvent the authentication process and authenticate as a legitimate cluster peer.

Frequently asked questions

What is CVE-2021-41025?: Multiple vulnerabilities in the authentication mechanism of confd in FortiWeb versions 6.4.1, 6.4.0, 6.3.0 through 6.3.15, 6.2.0 through 6.2.6, 6.1.0 through 6.1.2, 6.0.0 thorugh 6.0.7, including an instance of concurrent execution using shared resource with improper synchronization and one of authentication bypass by capture-replay, may allow a remote unauthenticated attacker to circumvent the authentication process and authenticate as a legitimate cluster peer.
How severe is CVE-2021-41025?: CVE-2021-41025 has a CVSS 3.x base score of 7.3, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.
Is CVE-2021-41025 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (70th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-41025?: CVE-2021-41025 primarily affects Fortinet Fortiweb. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-41025?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-41025 published?: CVE-2021-41025 was published on 2021-12-08 and last updated on 2026-06-17.

References

https://fortiguard.com/advisory/FG-IR-21-130

Affected products (7)

cpe:2.3:a:fortinet:fortiweb:*:*:*:*:*:*:*:*
cpe:2.3:a:fortinet:fortiweb:6.1.0:*:*:*:*:*:*:*
cpe:2.3:a:fortinet:fortiweb:6.1.1:*:*:*:*:*:*:*
cpe:2.3:a:fortinet:fortiweb:6.1.2:*:*:*:*:*:*:*
cpe:2.3:a:fortinet:fortiweb:6.4.0:*:*:*:*:*:*:*
cpe:2.3:a:fortinet:fortiweb:6.4.1:*:*:*:*:*:*:*
cpe:2.3:a:fortinet:fortiweb:6.4.2:*:*:*:*:*:*:*

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