Juniper · Auth bypass
Juniper ScreenOS Authentication Bypass Vulnerability
At a glance
Actively exploited in the wild — prioritise confirming exposure.
Medium rather than High: exposure is scored at a default because we cannot see your systems or suppliers. If you run or depend on Juniper ScreenOS, treat it as High.
Briefing
- Do not treat uncorroborated claims as confirmed breaches.
Questions to ask IT
- Do we run Juniper ScreenOS, and which versions?
- Is any of it reachable from the internet?
- Have we checked whether it has already been used against us?
- If it is not yet patched, what mitigation is in place, and will the fix be done by 11 Nov?
Next steps
- Confirm exposure, mitigation status and any service interruption risk.
Vulnerability facts
Full CVE detail CVE-2015-7755- 9.8 · CriticalExploitable over the network without any account, and no one has to click or open anything. High impact on confidentiality, integrity and availability.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Listed: attacks using it have been seen (on the catalogue since )
- Elevated attack likelihood (~61.1% in 30 days)
- 6.3.0r12 before 6.3.0r12b, 6.3.0r13 before 6.3.0r13b, 6.3.0r14 before 6.3.0r14b, 6.3.0r15 before 6.3.0r15b, 6.3.0r16 before 6.3.0r16b, 6.3.0r17 before 6.3.0r17b, 6.3.0r18 before 6.3.0r18b, 6.3.0r19 before 6.3.0r19b, 6.3.0r20 before 6.3.0r21, 6.2.0r18 and earlier
- 6.3.0r12b, 6.3.0r13b, 6.3.0r14b, 6.3.0r15b, 6.3.0r16b, 6.3.0r17b, 6.3.0r18b, 6.3.0r19b, 6.3.0r21
These facts are for CVE-2015-7755. This event covers 1 more CVE, each with its own record. Versions are as the CVE record states them; check the vendor advisory before planning a fix.
No technical write-up beyond these facts and the summary below yet.
Next steps
- Confirm whether affected products/versions are present and prioritise patching or mitigations
Summary
- Juniper ScreenOS contains an improper authentication vulnerability that could allow unauthorised remote administrative access to the device.
- CVE-2015-7755 is listed in known-exploited catalogue (exploitation in the wild)
- Authoritative catalogues report active exploitation of this vulnerability.
Why this matters in the UK
- Known-exploited catalogue reports exploitation in the wild
Products and services involved
- Juniper ScreenOS82% match confidence · CVE-2015-7755
Part of Adobe Commerce and Magento Improper Neutralization of Special Elements Used in a Template Engine Vulnerability
Pulse
Last checked 4d ago · Recheck overdue since 5 Nov 2026, 23:10 UK time · 3 quiet checks collapsed
in the next 30 days first recorded at 61.1% (elevated likelihood signal, not confirmed exploitation). Suggested changed to 7d.
Elevated — confirm exposure; this is a probability signal, not confirmed exploitation.
2 quiet checks hidden.
Sources
Juniper ScreenOS Improper Authentication Vulnerability
How we know
Statements extracted from sources. Higher confidence means stronger corroboration.
- ConfirmedHeadline90% confidence
Juniper ScreenOS Improper Authentication Vulnerability
- ConfirmedSummary fact75% confidence
Juniper ScreenOS contains an improper authentication vulnerability that could allow unauthorised remote administrative access to the device. Affects Juniper ScreenOS. Known ransomware campaign use: Unknown. Required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- ConfirmedCVE identifier95% confidence
Event involves CVE-2015-7755
- ConfirmedKnown-exploited catalogue98% confidence
CVE-2015-7755 is listed in known-exploited catalogue (exploitation in the wild)
- ConfirmedCVE identifier95% confidence
Event involves CVE-2015-7756