CVE-2023-27997

Exp

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.

Published: 2023-06-13 Last update: 2025-10-24 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-27997 is rated Critical Active Threat (98.9/100): CVSS Critical severity, with high exploitation likelihood (EPSS 91.91%, 100th percentile). CISA KEV confirms active exploitation (added 2023-06-13) affecting Fortinet / FortiOS and FortiProxy SSL-VPN. a weakness (CWE-122) Unauthenticated remote administrative access may be possible. The CISA remediation deadline has passed—treat as an emergency patch priority.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

CISA KEV Record for CVE-2023-27997

Name: Fortinet FortiOS and FortiProxy SSL-VPN Heap-Based Buffer Overflow Vulnerability · CISA KEV detail

Exploit added: 2023-06-13

Action due: 2023-07-04

Required action: Apply updates per vendor instructions.

Exploit prediction scoring system (EPSS) score for CVE-2023-27997

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-08 92.12% 91.91% -0.21%
2 2026-05-28 92.42% 92.12% -0.30%
3 2026-05-23 — 92.42% —

Full EPSS history (154 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-27997

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]

Weakness enumeration for CVE-2023-27997

Affected software / configurations for CVE-2023-27997

Vendor Product Version Raw CPE
fortinet fortiproxy >= 1.1.0, <= 1.1.6 cpe:2.3:a:fortinet:fortiproxy:*:*:*:*:*:*:*:*
fortinet fortiproxy >= 1.2.0, <= 1.2.13 cpe:2.3:a:fortinet:fortiproxy:*:*:*:*:*:*:*:*
fortinet fortiproxy >= 2.0.0, <= 2.0.12 cpe:2.3:a:fortinet:fortiproxy:*:*:*:*:*:*:*:*
fortinet fortiproxy >= 7.0.0, <= 7.0.9 cpe:2.3:a:fortinet:fortiproxy:*:*:*:*:*:*:*:*
fortinet fortiproxy >= 7.2.0, <= 7.2.3 cpe:2.3:a:fortinet:fortiproxy:*:*:*:*:*:*:*:*
fortinet fortios >= 6.0.0, <= 6.0.16 cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:*
fortinet fortios >= 6.2.0, <= 6.2.13 cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:*
fortinet fortios >= 6.4.0, <= 6.4.12 cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:*
fortinet fortios >= 7.0.0, <= 7.0.11 cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:*
fortinet fortios >= 7.2.0, <= 7.2.4 cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:*
fortinet fortios >= 6.0.12, <= 6.0.16 cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:*
fortinet fortios >= 6.2.9, <= 6.2.13 cpe:2.3:o:fortinet:fortios:*:*:*:*:*:*:*:*
fortinet fortios 6.0.10 cpe:2.3:o:fortinet:fortios:6.0.10:*:*:*:*:*:*:*
fortinet fortios 6.2.4 cpe:2.3:o:fortinet:fortios:6.2.4:*:*:*:*:*:*:*
fortinet fortios 6.2.6 cpe:2.3:o:fortinet:fortios:6.2.6:*:*:*:*:*:*:*
fortinet fortios 6.2.7 cpe:2.3:o:fortinet:fortios:6.2.7:*:*:*:*:*:*:*
fortinet fortios 6.4.2 cpe:2.3:o:fortinet:fortios:6.4.2:*:*:*:*:*:*:*
fortinet fortios 6.4.6 cpe:2.3:o:fortinet:fortios:6.4.6:*:*:*:*:*:*:*
fortinet fortios 6.4.8 cpe:2.3:o:fortinet:fortios:6.4.8:*:*:*:*:*:*:*
fortinet fortios 6.4.10 cpe:2.3:o:fortinet:fortios:6.4.10:*:*:*:*:*:*:*
fortinet fortios 6.4.12 cpe:2.3:o:fortinet:fortios:6.4.12:*:*:*:*:*:*:*
fortinet fortios 7.0.5 cpe:2.3:o:fortinet:fortios:7.0.5:*:*:*:*:*:*:*
fortinet fortios 7.0.10 cpe:2.3:o:fortinet:fortios:7.0.10:*:*:*:*:*:*:*

References for CVE-2023-27997

cvelogic Threat Intelligence