CVE-2015-7755

CVE-2015-7755 is a critical-severity (CVSS 9.8) vulnerability in Juniper ScreenOS. CISA added it to the Known Exploited Vulnerabilities catalog on October 2, 2025, which means exploitation in the wild has been confirmed; US federal agencies had to remediate it by October 23, 2025. CISA does not currently list it as used in ransomware campaigns. Juniper has 8 vulnerabilities in the KEV catalog, 0 of them linked to ransomware.

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 vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

• http://arstechnica.com/security/2015/12/unauthorized-code-in-juniper-firewalls-decrypts-encrypted-vpn-traffic/
• http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10713
• http://twitter.com/cryptoron/statuses/677900647560253442
• http://www.forbes.com/sites/thomasbrewster/2015/12/18/juniper-says-it-didnt-work-with-government-to-add-unauthorized-code-to-network-gear/
• http://www.kb.cert.org/vuls/id/640184
• http://www.securityfocus.com/bid/79626
• http://www.securitytracker.com/id/1034489
• http://www.wired.com/2015/12/juniper-networks-hidden-backdoors-show-the-risk-of-government-backdoors/