CVE-2015-7755

Exp

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.

Published: 2015-12-19 Last update: 2026-04-21 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2015-7755 is rated Critical Active Threat (99.6/100): CVSS Critical severity, with high exploitation likelihood (EPSS 85.80%, 99th percentile). CISA KEV confirms active exploitation (added 2025-10-02) affecting Juniper / ScreenOS. an authentication bypass (CWE-287) Unauthenticated remote administrative access may be possible. The CISA remediation deadline has passed—treat as an emergency patch priority.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

CISA KEV Record for CVE-2015-7755

Name: Juniper ScreenOS Improper Authentication Vulnerability · CISA KEV detail

Exploit added: 2025-10-02

Action due: 2025-10-23

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.

Public exploit references (Exploit-DB) for CVE-2015-7755

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2015-7755

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-28 85.16% 85.80% +0.63%
2 2026-04-22 84.95% 85.16% +0.21%
3 2026-03-27 — 84.95% —

Full EPSS history (32 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2015-7755

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 134c704f-9b21-4f2e-91b3-4a467353bcc0
10.0 2.0 HIGH
AV:N/AC:L/Au:N/C:C/I:C/A:C Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
 10.0 10.0 [email protected]

Weakness enumeration for CVE-2015-7755

Affected software / configurations for CVE-2015-7755

Vendor Product Version Raw CPE
juniper screenos 6.3.0 cpe:2.3:o:juniper:screenos:6.3.0:r17:*:*:*:*:*:*
juniper screenos 6.3.0 cpe:2.3:o:juniper:screenos:6.3.0:r18:*:*:*:*:*:*
juniper screenos 6.3.0 cpe:2.3:o:juniper:screenos:6.3.0:r19:*:*:*:*:*:*
juniper screenos 6.3.0 cpe:2.3:o:juniper:screenos:6.3.0:r20:*:*:*:*:*:*

References for CVE-2015-7755

URL Tags
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
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