Threats / Juniper / CVE-2015-7755
CVE-2015-7755
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-06-22
Juniper ScreenOS vulnerability
Juniper ScreenOS contains an improper authentication vulnerability allowing unauthorized remote administrative access to affected devices.
Verdict
Today item — known-exploited.
This authentication bypass in ScreenOS enables unauthenticated attackers to gain full administrative control of network security appliances. The high EPSS score and confirmed wild exploitation indicate active abuse targeting critical infrastructure.
01
Is it exploitable?
— the evidence, ranked above the scoreExploit available
Public proof-of-concept exploit code is cataloged for this vulnerability.We link the existence of the exploit; we do not host or redistribute payloads.
Reported exploitation
5 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2025-10-02).
Probability (EPSS)
EPSS 0.614 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Juniper, ScreenOS. Confirm exact fixed builds in the vendor advisory.
Weakness (CWE)
Mapped to CWE-287 Improper Authentication — weakness family: Authentication.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution not established
No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.
03
Why it matters
— the attack path, told twice: adversary, then board1
Front door — unauthenticated access narrative 1
Attacker
I craft a malicious authentication request to bypass credential validation in ScreenOS.
Business
Network perimeter security is compromised without detection or credential compromise.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I establish an authenticated administrative session on the target device.
Business
Attacker gains unrestricted access to firewall configuration, routing, and traffic inspection controls.
3
Lateral reach — past segmentation narrative 3
Attacker
I modify firewall rules, disable logging, and establish persistent backdoor access.
Business
Organization loses visibility into network traffic and cannot detect lateral movement or data exfiltration.
04
What to do
— defensible action- Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05