CVE-2015-7755

Juniper ScreenOS Improper Authentication

9.8 CRITICALActively exploited (CISA KEV)Public exploitEPSS 61.1%

Published19 Dec 2015
Added to CISA KEV2 Oct 2025
Remediation due23 Oct 2025

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 breakdown

Attack vectorNetwork

Attack complexityLow

Privileges requiredNone

User interactionNone

ScopeUnchanged

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

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

Affected products

Juniper Screenos6.3.0

Remediation

No fixed version is recorded in the NVD data. Check the vendor advisory for the latest guidance.

Patch & vendor advisories

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=JSA10713ExploitVendor 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
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

and 2 more references

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

Frequently asked

Is CVE-2015-7755 being actively exploited?

Yes. CVE-2015-7755 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added 2 Oct 2025.

How severe is CVE-2015-7755?

CVE-2015-7755 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 61.1% probability of exploitation.

Which products are affected by CVE-2015-7755?

Affected products include Juniper Screenos.

How do I fix CVE-2015-7755?

Apply the vendor's patch or advisory guidance, then verify no affected versions remain across your devices.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2015-7755 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. Because it is on the CISA KEV list, Secuno flags any affected asset as top-priority automatically. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.