Juniper ScreenOS up to 6.2.0r18/6.3.0r20 VPN improper authentication

CVSS Meta Temp Score
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CTI Interest Score
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5.4$0-$5k0.00

Summaryinfo

A vulnerability classified as critical was found in Juniper ScreenOS up to 6.2.0r18/6.3.0r20. The impacted element is an unknown function of the component VPN. Such manipulation leads to improper authentication. This vulnerability is documented as CVE-2015-7755. Additionally, an exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Juniper ScreenOS up to 6.2.0r18/6.3.0r20 (Router Operating System). It has been rated as critical. Affected by this issue is an unknown function of the component VPN. The manipulation with an unknown input leads to a improper authentication vulnerability. Using CWE to declare the problem leads to CWE-287. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. Impacted is confidentiality, integrity, and availability.

The weakness was released 12/17/2015 as JSA10713 as confirmed advisory (Website). The advisory is shared for download at kb.juniper.net. This vulnerability is handled as CVE-2015-7755 since 10/08/2015. The exploitation is known to be difficult. The attack may be launched remotely. No form of authentication is required for exploitation. Technical details are unknown but a public exploit is available. The advisory points out:

The second issue may allow a knowledgeable attacker who can monitor VPN traffic to decrypt that traffic. It is independent of the first issue.

The exploit is available at packetstormsecurity.com. It is declared as attacked. As 0-day the estimated underground price was around $5k-$25k. The vulnerability scanner Nessus provides a plugin with the ID 87507 (Juniper ScreenOS 6.2.x < 6.2.0r19 / 6.3.x < 6.3.0r21 Multiple Vulnerabilities (JSA10713)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Firewalls and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 38259 (SSH User Login Bruteforced). The advisory illustrates:

There is no way to detect that this vulnerability was exploited.
This issue was added on 10/02/2025 to the CISA Known Exploited Vulnerabilities Catalog with a due date of 10/23/2025:
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Upgrading to version 6.2.0r19 or 6.3.0r21 eliminates this vulnerability. A possible mitigation has been published immediately after the disclosure of the vulnerability. Furthermore it is possible to detect and prevent this kind of attack with TippingPoint and the filter 22309.

The vulnerability is also documented in the databases at Zero-Day.cz (265), Tenable (87507), SecurityFocus (BID 79626†), SecurityTracker (ID 1034489†) and Vulnerability Center (SBV-55336†). Entries connected to this vulnerability are available at VDB-14087, VDB-79855 and VDB-79874. If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.6
VulDB Meta Temp Score: 5.4

VulDB Base Score: 5.6
VulDB Temp Score: 5.4
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
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Exploitinginfo

Class: Improper authentication
CWE: CWE-287
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Access: Public
Status: Attacked
Download: 🔍

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KEV Added: 🔍
KEV Due: 🔍
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Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 87507
Nessus Name: Juniper ScreenOS 6.2.x < 6.2.0r19 / 6.3.x < 6.3.0r21 Multiple Vulnerabilities (JSA10713)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 802738
OpenVAS Name: Backdoor in ScreenOS
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

MetaSploit ID: juniper_backdoor.rb
MetaSploit Name: Juniper SSH Backdoor Scanner
MetaSploit File: 🔍

Zero-Day.cz: 🔍

Threat Intelligenceinfo

Interest: 🔍
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Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍

Upgrade: ScreenOS 6.2.0r19/6.3.0r21
Suricata ID: 2022291
Suricata Class: 🔍
Suricata Message: 🔍

TippingPoint: 🔍

McAfee IPS: 🔍
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Fortigate IPS: 🔍

Timelineinfo

10/08/2015 🔍
12/17/2015 +70 days 🔍
12/17/2015 +0 days 🔍
12/17/2015 +0 days 🔍
12/17/2015 +0 days 🔍
12/18/2015 +1 days 🔍
12/18/2015 +0 days 🔍
12/18/2015 +0 days 🔍
12/19/2015 +1 days 🔍
12/20/2015 +1 days 🔍
10/02/2025 +3574 days 🔍

Sourcesinfo

Vendor: juniper.net

Advisory: JSA10713
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2015-7755 (🔍)
GCVE (CVE): GCVE-0-2015-7755
GCVE (VulDB): GCVE-100-79856
CERT: 🔍
SecurityFocus: 79626 - Juniper ScreenOS CVE-2015-7755 Unauthorized Access and Information Disclosure Vulnerabilities
SecurityTracker: 1034489
Vulnerability Center: 55336 - Juniper ScreenOS <6.2.0r18, <6.3.0r21 Remote Host Privilege via SSH or Telnet Related to Log File, Critical

scip Labs: https://www.scip.ch/en/?labs.20161013
See also: 🔍

Entryinfo

Created: 12/18/2015 13:52
Updated: 10/02/2025 19:54
Changes: 12/18/2015 13:52 (73), 06/19/2018 21:00 (21), 07/01/2022 12:07 (3), 07/08/2024 06:39 (18), 09/01/2024 19:55 (2), 11/11/2024 08:32 (1), 10/01/2025 18:35 (1), 10/02/2025 19:54 (9)
Complete: 🔍
Cache ID: 216:039:103

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