What’s Vulnerable › Vulnerabilities

CVE-2023-31176: Insufficient entropy vulnerability could lead to authentication bypass

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.9% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2023-11-30 · updated 2026-06-17
• Weakness: CWE-331

Description

An Insufficient Entropy vulnerability in the Schweitzer Engineering Laboratories SEL-451 could allow an unauthenticated remote attacker to brute-force session tokens and bypass authentication.  See product Instruction Manual Appendix A dated 20230830 for more details.

Affected products

• Schweitzer Engineering Laboratories SEL-451: from r315-v0 before r315-v4; from r316-v0 before r316-v4; from r317-v0 before r317-v4; from r318-v0 before r318-v5; from r320-v0 before r320-v3; from r321-v0 before r321-v3 — fixed in r315-v4, r316-v4, r317-v4, r318-v5, r320-v3, r321-v3

How to fix

Upgrade to a fixed version: Schweitzer Engineering Laboratories SEL-451 r315-v4, r316-v4, r317-v4, r318-v5. Check the vendor advisory for mitigations.

References

• https://selinc.com/support/security-notifications/external-reports/
• https://www.nozominetworks.com/blog/
• https://selinc.com/support/security-notifications/external-reports/
• https://www.nozominetworks.com/blog/

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