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CVE-2023-27997

Fortinet FortiOS and FortiProxy SSL-VPN Heap-Based Buffer Overflow

9.8 CRITICALActively exploited (CISA KEV)Used in ransomwareEPSS 85.7%
  1. Published13 Jun 2023
  2. Added to CISA KEV13 Jun 2023
  3. Remediation due4 Jul 2023
Actively exploited (CISA KEV)

Fortinet FortiOS and FortiProxy SSL-VPN contain a heap-based buffer overflow vulnerability which can allow an unauthenticated, remote attacker to execute code or commands via specifically crafted requests.

Added to KEV: 13 Jun 2023Federal remediation due: 4 Jul 2023Used in ransomware

Description

A heap-based buffer overflow vulnerability [CWE-122] in FortiOS version 7.2.4 and below, version 7.0.11 and below, version 6.4.12 and below, version 6.0.16 and below and FortiProxy version 7.2.3 and below, version 7.0.9 and below, version 2.0.12 and below, version 1.2 all versions, version 1.1 all versions SSL-VPN may allow a remote attacker to execute arbitrary code or commands via specifically crafted requests.

CVSS 3.1 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionNone
ScopeUnchanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

Fortinet FortiProxy≥ 1.1.0 ≤ 1.1.6 · ≥ 1.2.0 ≤ 1.2.13 · ≥ 2.0.0 ≤ 2.0.12 · ≥ 7.0.0 ≤ 7.0.9
Fortinet FortiOS≥ 6.0.0 ≤ 6.0.16 · ≥ 6.0.12 ≤ 6.0.16 · ≥ 6.2.0 ≤ 6.2.13 · ≥ 6.2.9 ≤ 6.2.13

Remediation

No fixed version is recorded in the NVD data. Check the vendor advisory for the latest guidance.

References

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Frequently asked

Is CVE-2023-27997 being actively exploited?

Yes. CVE-2023-27997 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added 13 Jun 2023. It has been used in ransomware campaigns.

How severe is CVE-2023-27997?

CVE-2023-27997 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 85.7% probability of exploitation.

Which products are affected by CVE-2023-27997?

Affected products include Fortinet FortiProxy, Fortinet FortiOS.

How do I fix CVE-2023-27997?

Apply the vendor's patch or advisory guidance, then verify no affected versions remain across your devices.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2023-27997 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. Because it is on the CISA KEV list, Secuno flags any affected asset as top-priority automatically. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.