Horizon Alert
Summary of the vulnerability and why it matters
A vulnerability has been identified in a Reyrolle device that could allow an unauthenticated attacker to predict security-related values, potentially enabling them to impersonate legitimate users and gain unauthorized access.
- Predictable security values allow unauthorized access.
- Matters if the affected device is externally accessible.
- Confirm relevance and exposure for this specific asset.
Attack Path
How an attacker could exploit the issue
An unauthenticated attacker can remotely exploit this vulnerability by targeting the predictable random number generator used for security-sensitive values like session identifiers. By guessing these values, an attacker could impersonate a legitimate user to gain unauthorized access to the device.
- No authentication or network access needed.
- Predictable random numbers for session identifiers.
- Unauthorized access to the device.
Live Threat
Current exploitation, exposure, and threat context
The predictability of random number generation in Reyrolle 7SR5 devices could allow an unauthenticated remote attacker to impersonate a legitimate user, potentially gaining unauthorized access to the device. This is possible when the device is accessible remotely and its security-relevant values are not sufficiently protected.
- Protected device access.
- Predicting random number sequences.
- Unauthorized system access.
Operational Fix
Recommended remediation, mitigation, and detection steps
This vulnerability impacts industrial control systems, likely managed by infrastructure or operations technology (OT) teams. The first practical step is to identify all instances of the Reyrolle 7SR5, determine their network exposure, confirm business criticality, and then assign ownership for remediation planning.
- Own: Infrastructure and OT teams.
- Verify: Device network reachability and criticality.
- Action: Plan vendor-coordinated updates.
