How severe is CVE-2023-42789?

CVE-2023-42789 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2023-42789 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (87th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-42789?

CVE-2023-42789 primarily affects Fortinet Fortiproxy. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2023-42789?

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

Does CVE-2023-42789 have an EU (EUVD) identifier?

Yes. CVE-2023-42789 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2023-47219.

When was CVE-2023-42789 published?

CVE-2023-42789 was published on 2024-03-12 and last updated on 2026-06-17.

CVE-2023-42789

CVE-2023-42789 is a critical-severity vulnerability in Fortinet Fortiproxy with a CVSS 3.x base score of 9.8. 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-787.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 3% (87th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2023-47219
Weakness: CWE-787
Affected product: Fortinet Fortiproxy
Published: 2024-03-12
Last modified: 2026-06-17

Description

A out-of-bounds write in Fortinet FortiOS 7.4.0 through 7.4.1, 7.2.0 through 7.2.5, 7.0.0 through 7.0.12, 6.4.0 through 6.4.14, 6.2.0 through 6.2.15, FortiProxy 7.4.0, 7.2.0 through 7.2.6, 7.0.0 through 7.0.12, 2.0.0 through 2.0.13 allows attacker to execute unauthorized code or commands via specially crafted HTTP requests.

Frequently asked questions

What is CVE-2023-42789?: A out-of-bounds write in Fortinet FortiOS 7.4.0 through 7.4.1, 7.2.0 through 7.2.5, 7.0.0 through 7.0.12, 6.4.0 through 6.4.14, 6.2.0 through 6.2.15, FortiProxy 7.4.0, 7.2.0 through 7.2.6, 7.0.0 through 7.0.12, 2.0.0 through 2.0.13 allows attacker to execute unauthorized code or commands via specially crafted HTTP requests.
How severe is CVE-2023-42789?: CVE-2023-42789 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2023-42789 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (87th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-42789?: CVE-2023-42789 primarily affects Fortinet Fortiproxy. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-42789?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2023-42789 have an EU (EUVD) identifier?: Yes. CVE-2023-42789 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2023-47219.
When was CVE-2023-42789 published?: CVE-2023-42789 was published on 2024-03-12 and last updated on 2026-06-17.

References

https://fortiguard.com/psirt/FG-IR-23-328

Affected products (5)

cpe:2.3:a:fortinet:fortiproxy:*:*:*:*:*:*:*:*
cpe:2.3:a:fortinet:fortiproxy:7.4.0:*:*:*:*:*:*:*
cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:*
cpe:2.3:o:fortinet:fortios:7.4.0:*:*:*:*:*:*:*
cpe:2.3:o:fortinet:fortios:7.4.1:*:*:*:*:*:*:*

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