CVEs / CVE-2015-7755
CVE-2015-7755: Juniper ScreenOS Improper Authentication Vulnerability
- Known exploited in the CISA KEV catalog since 2 Oct 2025
- critical 9.8 CVSS 3.1 (NVD)
- EPSS 61.1% chance of exploitation in the next 30 days, higher than 99% of CVEs (30 Oct 2026)
- Last changed at its sources
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Summary
Juniper ScreenOS contains an improper authentication vulnerability that could allow unauthorized remote administrative access to the device.
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.
Affected and fixed versions
| Product | Affected | Fixed in |
|---|---|---|
| n/a n/a | n/a | — |
Exploitation
| In CISA KEV since | 2 Oct 2025 |
|---|---|
| Due date for US federal agencies | 23 Oct 2025 |
| Used in ransomware campaigns | 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. |
Severity
| CVSS 3.1 | 9.8 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HScored by NVD |
|---|---|
| Weakness | CWE-287 |
References
- CVE-2015-7755 on NVD
- CVE-2015-7755 in the CISA KEV catalog
- 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 (cited by CISA)
- 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=JSA10713 Exploit, Vendor Advisory
- http://twitter.com/cryptoron/statuses/677900647560253442 Broken 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/640184 Third Party Advisory
- http://www.securityfocus.com/bid/79626 Broken Link
- http://www.securitytracker.com/id/1034489 Broken 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/285554 Vendor Advisory
- https://github.com/hdm/juniper-cve-2015-7755 Third Party Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2015-7755 US Government Resource
Sources
Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.
This product uses data from the NVD API but is not endorsed or certified by the NVD.