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-2023-42789 is a critical-severity Out-of-bounds Write (CWE-787) vulnerability in Fortinet Fortios. Its CVSS base score is 9.8 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Security Account Manager (T1003.002); ranked in the top 12% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-15 (Development Process, Standards, and Tools) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2023-42789 is an out-of-bounds write vulnerability, tracked under CWE-787, that affects multiple versions of 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, and 6.2.0 through 6.2.15) as well as FortiProxy (7.4.0, 7.2.0 through 7.2.6, 7.0.0 through 7.0.12, and 2.0.0 through 2.0.13). The flaw carries a CVSS v3.1 score of 9.8 and permits execution of unauthorized code or commands when the affected devices process specially crafted HTTP requests.
An unauthenticated remote attacker can exploit the issue over the network without user interaction by sending malicious HTTP requests that trigger the out-of-bounds write, resulting in full compromise of confidentiality, integrity, and availability on the target device.
The Fortinet advisory FG-IR-23-328, referenced at fortiguard.com/psirt/FG-IR-23-328, supplies official guidance on mitigation and available patches for the listed FortiOS and FortiProxy releases. The associated EPSS score has remained near its observed peak of 0.3002 with a current value of 0.2828.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2023-47219
Vulnerability Data
A out-of-bounds write vulnerability in Fortinet FortiOS 7.4.0 through 7.4.1, FortiOS 7.2.0 through 7.2.5, FortiOS 7.0.0 through 7.0.12, FortiOS 6.4.0 through 6.4.14, FortiOS 6.2.0 through 6.2.15, FortiProxy 7.4.0, FortiProxy 7.2.0 through 7.2.6, FortiProxy 7.0.0 through 7.0.12, FortiProxy 2.0.0 through 2.0.13,…
more
FortiSASE 23.2.b allows attacker to execute unauthorized code or commands via specially crafted HTTP requests.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation (including fuzzing and bounds checks) finds out-of-bounds write flaws before deployment.
Requiring documented secure-development standards and tools can mandate bounds-checked coding practices that avoid the weakness.
Input validation can structurally reject or sanitize data that would otherwise trigger an out-of-bounds write.
Memory-protection mechanisms limit the exploitability and blast radius of a successful out-of-bounds write.
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 out-of-bounds write flaws so they can be remediated.
Patching or replacing vulnerable software directly eliminates known instances of this coding weakness.
Secure-development practices (static analysis, bounds checking, code review) are the primary means of preventing out-of-bounds writes.
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.