How severe is CVE-2020-15938?

CVE-2020-15938 has a CVSS 3.x base score of 4.0, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.

Is CVE-2020-15938 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (50th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-15938?

CVE-2020-15938 affects Fortinet Fortios. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-15938?

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

When was CVE-2020-15938 published?

CVE-2020-15938 was published on 2021-03-04 and last updated on 2026-06-17.

CVE-2020-15938

CVE-2020-15938 is a medium-severity vulnerability in Fortinet Fortios with a CVSS 3.x base score of 4.0. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: Medium (CVSS 3.x base score 4.0)
CVSS v2: 4.3
EPSS exploit prediction: 1% (50th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Fortinet Fortios
Published: 2021-03-04
Last modified: 2026-06-17

Description

When traffic other than HTTP/S (eg: SSH traffic, etc...) traverses the FortiGate in version below 6.2.5 and below 6.4.2 on port 80/443, it is not redirected to the transparent proxy policy for processing, as it doesn't have a valid HTTP header.

Frequently asked questions

What is CVE-2020-15938?: When traffic other than HTTP/S (eg: SSH traffic, etc...) traverses the FortiGate in version below 6.2.5 and below 6.4.2 on port 80/443, it is not redirected to the transparent proxy policy for processing, as it doesn't have a valid HTTP header.
How severe is CVE-2020-15938?: CVE-2020-15938 has a CVSS 3.x base score of 4.0, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2020-15938 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (50th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-15938?: CVE-2020-15938 affects Fortinet Fortios. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-15938?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-15938 published?: CVE-2020-15938 was published on 2021-03-04 and last updated on 2026-06-17.

References

https://fortiguard.com/advisory/FG-IR-20-172

Affected products (1)

cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:*

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