How severe is CVE-2021-43074?

CVE-2021-43074 has a CVSS 3.x base score of 4.3, 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 none, and availability none.

Is CVE-2021-43074 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (21st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-43074?

CVE-2021-43074 primarily affects Fortinet Fortiproxy. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-43074?

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

When was CVE-2021-43074 published?

CVE-2021-43074 was published on 2023-02-16 and last updated on 2026-06-17.

CVE-2021-43074

CVE-2021-43074 is a medium-severity vulnerability in Fortinet Fortiproxy with a CVSS 3.x base score of 4.3. 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-347.

Key facts

Severity: Medium (CVSS 3.x base score 4.3)
EPSS exploit prediction: 0% (21st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-347
Affected product: Fortinet Fortiproxy
Published: 2023-02-16
Last modified: 2026-06-17

Description

An improper verification of cryptographic signature vulnerability [CWE-347] in FortiWeb 6.4 all versions, 6.3.16 and below, 6.2 all versions, 6.1 all versions, 6.0 all versions; FortiOS 7.0.3 and below, 6.4.8 and below, 6.2 all versions, 6.0 all versions; FortiSwitch 7.0.3 and below, 6.4.10 and below, 6.2 all versions, 6.0 all versions; FortiProxy 7.0.1 and below, 2.0.7 and below, 1.2 all versions, 1.1 all versions, 1.0 all versions may allow an attacker to decrypt portions of the administrative session management cookie if able to intercept the latter.

Frequently asked questions

What is CVE-2021-43074?: An improper verification of cryptographic signature vulnerability [CWE-347] in FortiWeb 6.4 all versions, 6.3.16 and below, 6.2 all versions, 6.1 all versions, 6.0 all versions; FortiOS 7.0.3 and below, 6.4.8 and below, 6.2 all versions, 6.0 all versions; FortiSwitch 7.0.3 and below, 6.4.10 and below, 6.2 all versions, 6.0 all versions; FortiProxy 7.0.1 and below, 2.0.7 and below, 1.2 all versions, 1.1 all versions, 1.0 all versions may allow an attacker to decrypt portions of the administrative session management cookie if able to intercept the latter.
How severe is CVE-2021-43074?: CVE-2021-43074 has a CVSS 3.x base score of 4.3, 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 none, and availability none.
Is CVE-2021-43074 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (21st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-43074?: CVE-2021-43074 primarily affects Fortinet Fortiproxy. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-43074?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-43074 published?: CVE-2021-43074 was published on 2023-02-16 and last updated on 2026-06-17.

References

https://fortiguard.com/psirt/FG-IR-21-126

Affected products (4)

cpe:2.3:a:fortinet:fortiproxy:*:*:*:*:*:*:*:*
cpe:2.3:a:fortinet:fortiweb:*:*:*:*:*:*:*:*
cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:*
cpe:2.3:o:fortinet:fortiswitch:*:*:*:*:*:*:*:*

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