CVE-2023-36846VulnerabilityPublished 17 Aug 2023Updated 21 Oct 2025

CVE-2023-36846: Juniper Networks Junos OS · Missing Authentication

Affects Juniper Networks Junos OSSource CVE Database V5

Exploited in the wild · KEV due 17 Nov 2023 · 93% EPSS : apply the vendor's fix or mitigations to Juniper Networks Junos OS now.

Data as of 26 Oct 2026, 06:26 UTC

CVSS 3.1 base score

5.3Medium

How severe the flaw is on the 0–10 CVSS scale.

KEV deadline: 17 Nov 2023 US federal agencies must patch by this date; a sensible deadline for everyone else.
EPSS: 93.4% chance of exploitation in 30 days – higher than 99% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

t = 0 is the CVE’s publication on cve.org

Disclosed: evidence found.
CVE published 17 Aug 2023
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: evidence found.
Listed in CISA KEV 88 days after disclosure
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

CVE ID reserved
by juniper
2023-06-2716:17Z, 51 days before disclosure
CVE published
on cve.org
2023-08-1719:18Z, t = 0
Added to CISA KEV (opens in a new tab)
exploitation confirmed
2023-11-13, 88 days after disclosure
KEV remediation due
US federal deadline
2023-11-17, 92 days after disclosure

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA KEV (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Affected software

Product	Affected	Fixed in
Juniper Networks Junos OS	Affected =0 =21.1 =21.2 =21.3 =21.4 =22.1 =22.2 =22.3 =22.4	Fixed in–

Check the firmware or software version for Juniper Networks Junos OS in the device's admin interface against the vendor advisory.

Description

A Missing Authentication for Critical Function vulnerability in Juniper Networks Junos OS on SRX Series allows an unauthenticated, network-based attacker to cause limited impact to the file system integrity. With a specific request to user.php that doesn't require authentication an attacker is able to upload arbitrary files via J-Web, leading to a loss of integrity for a certain part of the file system, which may allow chaining to other vulnerabilities. This issue affects Juniper Networks Junos OS on SRX Series: * All versions prior to 20.4R3-S8; * 21.1 versions 21.1R1 and later; * 21.2 versions prior to 21.2R3-S6; * 21.3 versions prior to 21.3R3-S5; * 21.4 versions prior to 21.4R3-S5; * 22.1 versions prior to 22.1R3-S3; * 22.2 versions prior to 22.2R3-S2; * 22.3 versions prior to 22.3R2-S2, 22.3R3; * 22.4 versions prior to 22.4R2-S1, 22.4R3.

Impact

For European organizations, the impact of CVE-2023-36846 can be significant, particularly for those relying on Juniper SRX Series devices for firewalling, VPN, and network security functions. Successful exploitation could allow attackers to upload malicious files, potentially leading to unauthorized code execution, persistence, or lateral movement within the network. This undermines the integrity of the device's file system and could compromise the security posture of the entire network segment protected by the affected device. Critical infrastructure providers, financial institutions, telecommunications companies, and large enterprises in Europe that deploy Juniper SRX devices are at heightened risk. The vulnerability's remote and unauthenticated nature increases the attack surface, especially if the J-Web interface is exposed to untrusted networks or insufficiently segmented internal networks. Although no availability or confidentiality impact is directly indicated, chained exploits could escalate the severity. The medium severity rating suggests a moderate but non-negligible risk that requires prompt attention to avoid potential breaches or service disruptions.

Mitigation

1. Immediately apply the latest Juniper Networks patches for Junos OS as specified for each affected version branch (e.g., 20.4R3-S8, 21.2R3-S6, 22.4R2-S1, etc.). 2. Restrict access to the J-Web management interface by limiting it to trusted administrative networks using firewall rules or network segmentation. 3. Disable the J-Web interface if it is not required for operational purposes to reduce the attack surface. 4. Implement strong network access controls and monitoring on management interfaces to detect and block unauthorized access attempts. 5. Regularly audit device configurations and logs for signs of suspicious file uploads or unauthorized changes. 6. Employ multi-factor authentication and role-based access controls for device management where possible to add layers of defense. 7. Conduct vulnerability scanning and penetration testing focused on management interfaces to identify similar weaknesses proactively. 8. Maintain an incident response plan that includes procedures for compromised network devices to quickly isolate and remediate affected systems.

CWE-306Missing Authentication for Critical Function (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #21OWASP Top 10 A07:2025: Authentication Failures (opens in a new tab)
The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.
Architecture and Design
Divide the software into anonymous, normal, privileged, and administrative areas. Identify which of these areas require a proven user identity, and use a centralized authentication capability.
Architecture and Design
For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks…
Architecture and Design
Where possible, avoid implementing custom, "grow-your-own" authentication routines and consider using authentication capabilities as provided by the surrounding framework, operating system, or environment.
OWASP Cheat Sheets
OWASP Authentication (opens in a new tab)
OWASP ASVS 4.0.3
V1.2.3 (opens in a new tab)
V1.2.2 (opens in a new tab)
V1.2.4 (opens in a new tab)
Attack patterns
Choosing Message Identifier (opens in a new tab)
Force the System to Reset Values (opens in a new tab)
Using Unpublished Interfaces or Functionality (opens in a new tab)
Cross Site Request Forgery (opens in a new tab)
Communication Channel Manipulation (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

Timeline

What to do

Affected software

Description

AI analysisMachine-generated, updated 21 Oct 2025, 20:48 UTC

WeaknessesCWE-306

Technical details

References

Community reviews

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