How severe is CVE-2015-7755?

CVE-2015-7755 has a CVSS score of 9.8/10, rated CRITICAL. Immediate patching is strongly recommended.

Which products are affected by CVE-2015-7755?

Affected package information for CVE-2015-7755 is not yet fully mapped. Check the official advisory links for details.

How do I patch CVE-2015-7755?

No patch has shipped for CVE-2015-7755 yet — track the juniper screenos advisory for a fixed release and apply the workarounds below in the meantime.

How do I detect CVE-2015-7755 across my infrastructure?

Inventory every juniper screenos deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for exploitation at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.

How do I mitigate CVE-2015-7755 if there is no patch (or I can't update yet)?

Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.

How does O3 Security protect against CVE-2015-7755?

O3 detects and blocks CVE-2015-7755 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.

Is CVE-2015-7755 actively exploited in the wild?

Yes. There are 5 known exploit references for CVE-2015-7755, including 4 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2015-7755?

CVE-2015-7755 has an EPSS (Exploit Prediction Scoring System) score of 61.4%, placing it in the 99th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. A score above 50% indicates significantly elevated exploitation risk — immediate patching is strongly recommended.

Is CVE-2015-7755 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2015-7755 (Juniper ScreenOS Improper Authentication Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2025-10-02. CISA required all US federal civilian agencies to remediate this vulnerability by 2025-10-23. The required action was: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

What type of vulnerability is CVE-2015-7755?

CVE-2015-7755 is classified as Improper Authentication (CWE-287). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

Which products and versions are affected by CVE-2015-7755?

CVE-2015-7755 affects juniper screenos (1 version, e.g. 6.3.0). Check the affected-products list on this page against your deployed version to confirm exposure.

Is there exploit tooling available for CVE-2015-7755?

A Metasploit module references CVE-2015-7755, which lowers the barrier to weaponization. Public exploit tooling significantly increases real-world risk — prioritize patching and ensure detection coverage. Exploit tooling should only ever be used in isolated, authorized testing environments.

When was CVE-2015-7755 published, and has it been updated?

CVE-2015-7755 was published on December 19, 2015 and was last updated on June 17, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CISA KEV·Added 2025-10-02 — agencies required to remediate by 2025-10-23

CVE-2015-7755

CRITICAL

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…

Published

Dec 19, 2015

Updated

Jun 17, 2026

Affected

0 pkgs

Patched

None yet

Exploits

5 known

EPSS Exploitation Probability

via FIRST.org ↗

61.4%probability of exploitation in next 30 days

High Risk99th percentile0.00%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

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 Products

1 product · 4 configurations

screenosjuniper

1 version

6.3.0

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

Juniper ScreenOS 6.2.0r15 through 6.2.0r18, 6.3.0r12 before 6.3.0r12b, 6…

kb.juniper.netNVDDec 2016

Juniper ScreenOS 6.2.0r15 through 6.2.0r18, 6.3.0r12 before 6.3.0r12b, 6…

github.comMetasploitOct 2020

Juniper ScreenOS 6.2.0r15 through 6.2.0r18, 6.3.0r12 before 6.3.0r12b, 6…

github.comGithubDec 2015

Juniper ScreenOS 6.2.0r15 through 6.2.0r18, 6.3.0r12 before 6.3.0r12b, 6…

github.comGithubJan 2016

Detection & mitigation playbook

Vendor / appliance

Detect
Inventory every juniper screenos deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for exploitation at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.
Remediation status
No patch has shipped for CVE-2015-7755 yet — track the juniper screenos advisory for a fixed release and apply the workarounds below in the meantime.
Mitigate without a patch
Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.
How O3 protects you
O3 detects and blocks CVE-2015-7755 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.

Tailored to CVE-2015-7755. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

O3 Security · Runtime Protection

Is CVE-2015-7755 being exploited in your environment?

O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2015-7755 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.

Protect my workloads How runtime protection works

CVSS Score

9.8/10

CVSS v3 base score

Vector breakdown

AV:Attack Vector

Network

AC:Attack Complexity

Low

PR:Privileges Required

None

UI:User Interaction

None

S:Scope

Unchanged

C:Confidentiality

High

I:Integrity

High

A:Availability

High

Raw vector

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

CWE Classification

CWE-287Improper Authentication

Weaponization

Timeline

Disclosed

Dec 19, 2015

First exploit

Dec 7, 2016

KEV added

Oct 2, 2025

Last updated

Jun 17, 2026

Identifiers

CVE-2015-7755

Data from OSV.dev, enriched by O3 Security. Refreshed hourly.

CVE-2015-7755

EPSS Exploitation Probability

Description

Affected Products

Detection & mitigation playbook

Detect

Remediation status

Mitigate without a patch

How O3 protects you

Frequently Asked Questions

Is CVE-2015-7755 being exploited in your environment?