CVE-2015-7755
Juniper ScreenOS Improper Authentication Vulnerability
Does this matter?
Known to be exploited in the wild (CISA KEV, CISA remediation deadline 23 October 2025). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.
Description
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.
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 61.14% probability · 99th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Listed 2 October 2025 · due 23 October 2025
- Weakness
- CWE-287
- Affected
- juniper/screenos
- Source
- cve@mitre.org
EPSS 61.1% since 30 October 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
CISA notes
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. https://supportportal.juniper.net/s/article/2015-12-Out-of-Cycle-Security-Bulletin-ScreenOS-Multiple-Security-issues-with-ScreenOS-CVE-2015-7755-CVE-2015-7756 ; https://nvd.nist.gov/vuln/detail/CVE-2015-7755
References
- http://arstechnica.com/security/2015/12/unauthorized-code-in-juniper-firewalls-decrypts-encrypted-vpn-traffic/Third Party Advisory
- http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10713Exploit, Vendor Advisory
- http://twitter.com/cryptoron/statuses/677900647560253442Broken Link
- http://www.forbes.com/sites/thomasbrewster/2015/12/18/juniper-says-it-didnt-work-with-government-to-add-unauthorized-code-to-network-gear/Permissions Required
- http://www.kb.cert.org/vuls/id/640184Third Party Advisory
- http://www.securityfocus.com/bid/79626Broken Link
- http://www.securitytracker.com/id/1034489Broken Link
- http://www.wired.com/2015/12/juniper-networks-hidden-backdoors-show-the-risk-of-government-backdoors/Third Party Advisory
- https://adamcaudill.com/2015/12/17/much-ado-about-juniper/Third Party Advisory
- https://forums.juniper.net/t5/Security-Incident-Response/Important-Announcement-about-ScreenOS/ba-p/285554Vendor Advisory
- https://github.com/hdm/juniper-cve-2015-7755Third Party Advisory
- http://arstechnica.com/security/2015/12/unauthorized-code-in-juniper-firewalls-decrypts-encrypted-vpn-traffic/Third Party Advisory
- http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10713Exploit, Vendor Advisory
- http://twitter.com/cryptoron/statuses/677900647560253442Broken Link
- http://www.forbes.com/sites/thomasbrewster/2015/12/18/juniper-says-it-didnt-work-with-government-to-add-unauthorized-code-to-network-gear/Permissions Required
- http://www.kb.cert.org/vuls/id/640184Third Party Advisory
- http://www.securityfocus.com/bid/79626Broken Link
- http://www.securitytracker.com/id/1034489Broken Link
- http://www.wired.com/2015/12/juniper-networks-hidden-backdoors-show-the-risk-of-government-backdoors/Third Party Advisory
- https://adamcaudill.com/2015/12/17/much-ado-about-juniper/Third Party Advisory
- https://forums.juniper.net/t5/Security-Incident-Response/Important-Announcement-about-ScreenOS/ba-p/285554Vendor Advisory
- https://github.com/hdm/juniper-cve-2015-7755Third Party Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2015-7755US Government Resource
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.