CVE-2015-7755 Juniper CVE debrief

Who should care

Organizations that still operate Juniper ScreenOS appliances, along with security teams responsible for perimeter devices, VPN gateways, or legacy network infrastructure, should treat this as a high-priority remediation item because it appears in CISA’s KEV catalog.

Technical summary

The supplied corpus identifies the issue only as an improper authentication vulnerability in Juniper ScreenOS. CISA’s KEV record indicates the vulnerability is known to be exploited and references Juniper’s security bulletin as the vendor guidance source. No further exploit mechanics are included in the provided materials.

Defensive priority

High. CISA added the vulnerability to the KEV catalog on 2025-10-02 with a remediation due date of 2025-10-23, which makes timely mitigation or removal of affected ScreenOS deployments the priority.

Recommended defensive actions

• Identify any Juniper ScreenOS devices in the environment and confirm whether they are affected by CVE-2015-7755.
• Apply Juniper’s mitigations or vendor guidance referenced by CISA as soon as possible.
• If mitigations are not available or cannot be applied reliably, discontinue use of the product.
• Validate whether compensating controls reduce exposure while remediation is planned.
• Track completion against the CISA KEV due date of 2025-10-23 for this entry.

Evidence notes

CISA’s Known Exploited Vulnerabilities record names the issue as “Juniper ScreenOS Improper Authentication Vulnerability,” lists vendorProject Juniper and product ScreenOS, and sets dateAdded to 2025-10-02 with dueDate 2025-10-23. The KEV metadata also cites Juniper’s out-of-cycle security bulletin for CVE-2015-7755/CVE-2015-7756 and states the required action is to apply vendor mitigations or discontinue use if mitigations are unavailable. The supplied corpus does not include additional technical detail beyond the improper-authentication classification.

Official resources