CVE intelligence and bounded remediation
CVE-2020-12820 — Fortinet Fortios security vulnerability
Under non-default configuration, a stack-based buffer overflow in FortiOS version 6.0.10 and below, version 5.6.12 and below may allow a remote attacker authenticated to the SSL VPN to crash the FortiClient NAC daemon (fcnacd) and potentially execute arbitrary code via requesting a large FortiClient file name. We are not aware of proof of concept code successfully achieving the latter.
- Severity
- High
- CVSS
- 8.8 (3.1)
- Published
- 2024-12-19
- CISA KEV
- Not currently listed
- Ecosystem
- operating-system
- Weaknesses
- CWE-121, CWE-787
Affected products
- fortinet / fortios
Showing 1 representative product identities from 2 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.
Matched remediation archetype
Buffer bounds, memory safety, and memory corruption
This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.
Check exposure
- Identify affected native-code versions, build flags, architectures, parsers, codecs, drivers, and input paths in all shipped artifacts.
- Determine whether untrusted data reaches the affected routine and the process privilege, sandbox, and network exposure.
- Confirm statically linked, vendored, firmware, and platform-provided copies, not only package-manager records.
Remediate safely
- Apply the maintained upstream correction or replace the affected component, then rebuild every dependent artifact from clean inputs.
- Adopt bounds-checked interfaces, validated sizes and integer conversions, clear ownership, and memory-safe components where practical.
- Enable supported compiler and runtime hardening and add sanitized tests and fuzz regression seeds derived from non-weaponized fixtures.
Authoritative sources
Complete CVE record and remediation plan
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