CVE-2019-15703

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.0% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2019-10-24 · updated 2026-06-17
Weakness: CWE-331

Description

An Insufficient Entropy in PRNG vulnerability in Fortinet FortiOS 6.2.1, 6.2.0, 6.0.8 and below for device not enable hardware TRNG token and models not support builtin TRNG seed allows attacker to theoretically recover the long term ECDSA secret in a TLS client with a RSA handshake and mutual ECDSA authentication via the help of flush+reload side channel attacks in FortiGate VM models only.

Affected products

Fortinet FortiOS (FortiGate): through 5.6.9; from 6.0.0 before 6.0.9; from 6.2.0 before 6.2.3 — fixed in 6.0.9, 6.2.3

How to fix

Upgrade to a fixed version: Fortinet FortiOS (FortiGate) 6.0.9, 6.2.3. Check the vendor advisory for mitigations.

References

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