CVE-2015-7755: Juniper ScreenOS Improper Authentication Vulnerability
Advisory generated from the CVE record, CISA, Exploit Observer and VEDAS: what it is, whether it is exploited, who is affected, and how to fix and detect it.
Generated by VEDAS. Scores as of 2026-11-01 19:19 UTC. Rebuilt every few hours from cve-scores, CISA KEV and vedas-signatures. How this works and its limits.
What it is
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.
Description quoted from the CVE record (assigned by mitre, published 2015-12-19).
Weakness: CWE-287 Improper Authentication
How it can be exploited
Exploitable over the network with low attack complexity needing no privileges and no user interaction. Impact: confidentiality high, integrity high, availability high. CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA assessment (SSVC): CISA assesses exploitation as active. Automatable: yes. Technical impact: total.
- On CISA KEV since
- 2025-10-02
- US federal deadline
- 2025-10-23
- Ransomware use
- Not known
Public exploit evidence (Exploit Observer)
Also known as: BDU:2015-12233, BDU:2015-12234, BDU:2015-12265, CNNVD-201512-540, CNVD-2015-08307, EUVD-2015-7655, GHSA-43vr-5w6h-pr3g
VEDAS cluster: VEDAS:BEECHSEAHORSE
Exploit Observer links 2 pieces of public exploit code or detection modules that name this CVE or one of its aliases.
Exploit code and modules (2)
Code that names this CVE. A repository can be a working exploit, a scanner, a fake or malware; read it before running anything.
- Code repository: https://github.com/cinno/cve-2015-7755-poc
- Code repository: https://github.com/hdm/juniper-cve-2015-7755
Vulnerability databases and vendor advisories (6)
Catalogue entries, not exploit evidence.
- Vulnerability database or vendor advisory: https://euvd.enisa.europa.eu/enisa/EUVD-2015-7655
- Vulnerability database or vendor advisory: https://github.com/advisories/GHSA-43vr-5w6h-pr3g
- Vulnerability database or vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2015-7755
- Vulnerability database or vendor advisory: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2015-7755
- Vulnerability database or vendor advisory: https://www.cnnvd.org.cn/home/globalSearch?keyword=CNNVD-201512-540
- Vulnerability database or vendor advisory: https://www.cnvd.org.cn/flaw/show/CNVD-2015-08307
35 more references returned by Exploit Observer did not name this CVE or an alias, so they are left out.
VEDAS data as of 2026-11-01T17:12 UTC; fetched 2026-11-02.
Live scores
- EPSS
- 0.611
very likely to be attacked soon - VEDAS
- 0.985
strong exploit evidence - On CISA KEV
- Yes, since 2025-10-02
- Detection rule
- None yet
Thin horizontal line: the “likely” (EPSS 0.10) or “strong” (VEDAS 0.90) threshold. Shaded “no data” areas are periods when cve-scores did not publish. The vertical line is the day CISA added it to its exploited list.
VEDAS flagged this bug about 46 days before CISA confirmed attacks.
Who is affected
| Product | Affected | Not affected |
|---|---|---|
| Not stated | version n/a | Not stated |
Version ranges exactly as the CVE record states them. “Before X” means X is the first fixed version.
How to fix it
CISA 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.
Vendor guidance:
- 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
How to detect it
There is no open VEDAS detection rule for this bug yet. It is listed on the detection gaps page if CISA has confirmed attacks.
References
Exploits and technical analysis
- VU#640184 (third-party-advisory)
Government sources
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2015-7755 (government-resource)
Other references
- http://arstechnica.com/security/2015/12/unauthorized-code-in-juniper-firewalls-decrypts-encrypted-vpn-traffic/
- http://www.wired.com/2015/12/juniper-networks-hidden-backdoors-show-the-risk-of-government-backdoors/
- 1034489 (vdb-entry)
- https://forums.juniper.net/t5/Security-Incident-Response/Important-Announcement-about-ScreenOS/ba-p/285554
- https://github.com/hdm/juniper-cve-2015-7755
- http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10713
- http://twitter.com/cryptoron/statuses/677900647560253442
- https://adamcaudill.com/2015/12/17/much-ado-about-juniper/
- http://www.forbes.com/sites/thomasbrewster/2015/12/18/juniper-says-it-didnt-work-with-government-to-add-unauthorized-code-to-network-gear/
- 79626 (vdb-entry)
Other databases
Where this comes from
This advisory is generated automatically by VEDAS from: CVE.org record, CISA KEV, cve-scores (EPSS and VEDAS), Exploit Observer. Text in quotes is reproduced from the source; everything else is a fixed template filled with source fields. Nothing here is written by a language model. Check the vendor advisory before acting, and read how VEDAS and Exploit Observer work, and their limits.