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CVE-2023-27997

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…

Critical9.2Known exploitedPublic exploitEPSS 85.7%
Published
Updated
Reserved
Assigned by
fortinet

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.

Exploited in the wild

CISA lists this vulnerability in its Known Exploited Vulnerabilities catalog as Fortinet FortiOS and FortiProxy SSL-VPN Heap-Based Buffer Overflow Vulnerability.

Added
13 Jun 2023
Fix due (US federal)
4 Jul 2023
Used by ransomware
Known

Apply updates per vendor instructions.

Public exploit

An exploit or proof of concept is public: anyone can try it against an unpatched system. CISA's SSVC rates its exploitation: it is being exploited.

Timeline

  1. ID reserved

    By fortinet

  2. · 3 months later

    Published

  3. Added to CISA KEV

    Known exploited, also by ransomware

  4. · 3 years later

    Record updated

Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.

Scores

CVSS scores of CVE-2023-27997, by who scored it
Scored byCVSSScoreVector
fortinetCNA (assigner)3.1Critical9.2CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:F/RL:X/RC:R
NVDNVD · Analyzed3.1Critical9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS (exploitation in 30 days)
85.7% · top 0.3% of all CVEs (8 Nov 2026)
CISA SSVC
Exploitation: active · Automatable: yes · Technical impact: total
Loading the EPSS history…

The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.2.

Weakness

Affected products

  • Fortinet · FortiOS-6K7K

    • affected 7.0.10
    • affected 7.0.5
    • affected 6.4.12
    • affected 6.4.10
    • affected 6.4.8
    • affected 6.4.6
    • affected 6.4.2
    • affected 6.2.9 – ≤ 6.2.13
    • affected 6.2.6 – ≤ 6.2.7
    • affected 6.2.4
    • affected 6.0.12 – ≤ 6.0.16
    • affected 6.0.10

  • Fortinet · FortiProxy

    • affected 7.2.0 – ≤ 7.2.3
    • affected 7.0.0 – ≤ 7.0.9
    • affected 2.0.0 – ≤ 2.0.12
    • affected 1.2.0 – ≤ 1.2.13
    • affected 1.1.0 – ≤ 1.1.6

  • Fortinet · FortiOS

    • affected 7.2.0 – ≤ 7.2.4
    • affected 7.0.0 – ≤ 7.0.11
    • affected 6.4.0 – ≤ 6.4.12
    • affected 6.2.0 – ≤ 6.2.13
    • affected 6.0.0 – ≤ 6.0.16

What to do

Solution: Please upgrade to FortiOS-6K7K version 7.0.12 or above Please upgrade to FortiOS-6K7K version 6.4.13 or above Please upgrade to FortiOS-6K7K version 6.2.15 or above Please upgrade to FortiOS-6K7K version 6.0.17 or above Please upgrade to FortiProxy version 7.2.4 or above Please upgrade to FortiProxy version 7.0.10 or above Please upgrade to FortiOS version 7.4.0 or above Please upgrade to FortiOS version 7.2.5 or above Please upgrade to FortiOS version 7.0.12 or above Please upgrade to FortiOS version 6.4.13 or above Please upgrade to FortiOS version 6.2.14 or above Please upgrade to FortiOS version 6.0.17 or above

References (2)

Sources

The same CVE in the primary databases and aggregators, to check against.

Badge for a README or a ticket

CVE-2023-27997 badge
[![CVE-2023-27997](https://cveledger.app/badge/CVE-2023-27997.svg)](https://cveledger.app/cve/CVE-2023-27997)

Record last updated .