PatchTheCVECVE-2015-7755: Juniper ScreenOS Improper Authentication Vulnerability
CVE-2015-7755 is a critical-severity flaw (CVSS 9.8) affecting screenos, reported as exploited in the wild. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
Juniper ScreenOS 6.2.0r15 through 6.2.0r18, 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, and 6.3.0r20 before 6.3.0r21 allows remote attackers to obtain administrative access by entering an unspecified password during a (1) SSH or (2) TELNET session.
Why this priority
- Critical severity
- EPSS top 1%: very likely to be exploited
- Exploited in the wild (CISA KEV)
- Public exploit reference
- CISA SSVC: automatable with total technical impact
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 9.8 (Critical) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 61.1% (top 1%) |
| CISA exploited list | Yes, fix due 2025-10-23 |
| Weakness | CWE-287 |
| Published | 2015-12-19 |
| Last modified | 2026-06-17 |
Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Exploited Added to the CISA Known Exploited Vulnerabilities list
- Deadline CISA due date for US federal agencies to patch
- Updated Record last modified
Exact fixes by distribution
Public exploits and detection
Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.
- GitHub PoC: hdm/juniper-cve-2015-7755 (105 stars)
- GitHub PoC: cinno/CVE-2015-7755-POC (2 stars)
- Write-up: forums.juniper.net/t5/Security-Incident-Response/Important-Announcement-about-ScreenOS/ba-
- Metasploit: Juniper SSH Backdoor Scanner
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2015-7755?
screenos: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.
Is CVE-2015-7755 being exploited?
Yes. CVE-2015-7755 is on the CISA Known Exploited Vulnerabilities list, so treat it as patch-now.
What does CVE-2015-7755 affect?
CVE-2015-7755 affects screenos. Severity is critical (CVSS 9.8). Juniper ScreenOS 6.2.0r15 through 6.2.0r18, 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, 6.3.0r1
How urgent is CVE-2015-7755?
Priority 97/100. Critical severity; EPSS top 1%: very likely to be exploited; Exploited in the wild (CISA KEV); Public exploit reference; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action
Software pages
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