Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2023-27997 is a critical-severity Heap-based Buffer Overflow (CWE-122) vulnerability in Fortinet Fortios. Its CVSS base score is 9.8 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Data Obfuscation (T1001); ranked in the top 0.3% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
A heap-based buffer overflow vulnerability, tracked as CWE-122 and CWE-787, affects the SSL-VPN component of FortiOS versions 7.2.4 and below, 7.0.11 and below, 6.4.12 and below, and 6.0.16 and below, as well as FortiProxy versions 7.2.3 and below, 7.0.9 and below, 2.0.12 and below, and all versions of 1.2 and 1.1. The flaw permits remote attackers to supply specially crafted requests that trigger memory corruption, leading to arbitrary code or command execution. It carries a CVSS 3.1 base score of 9.8, reflecting network-accessible, unauthenticated attack vectors with high impact on confidentiality, integrity, and availability.
An unauthenticated remote attacker can target exposed SSL-VPN interfaces to achieve full code execution on affected Fortinet appliances without user interaction. Successful exploitation grants the attacker the ability to run arbitrary commands, potentially resulting in complete device compromise, lateral movement, or persistence within the target network.
Fortinet’s PSIRT advisory FG-IR-23-097 details the affected releases and remediation steps, while CISA’s Known Exploited Vulnerabilities catalog confirms active exploitation in the wild. The associated EPSS score has remained consistently high, with a current value of 0.9141 and a recorded peak of 0.9242, underscoring sustained attacker interest following disclosure.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2023-31722
Vulnerability Data
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…
more
all versions, version 1.1 all versions SSL-VPN may allow a remote attacker to execute arbitrary code or commands via specifically crafted requests.
- CWE(s)
- KEV Date Added
- 13 June 2023
Related Threats
Threat-Actor AttributionAI
MITRE ATT&CK Enterprise Techniques
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Affected Assets
Mitigating Controls
Control response
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V1.4.1
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Out-of-bounds writes that corrupt control flow or inject shellcode are rendered non-executable by the same memory protections.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Vulnerability scanning and recording can discover heap-overflow flaws but does not prevent their introduction in code.
Timely patching removes known heap-overflow instances after they exist.
Secure-development practices directly require bounds checking and safe memory handling that prevent heap overflows.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.