CVE-2025-52989VulnerabilityPublished 11 Jul 2025Updated 24 Sep 2025

CVE-2025-52989: Juniper Networks Junos OS · Improper Neutralization of Delimiters

Affects Juniper Networks Junos OSSource CVE Database V5

Not known to be exploited · CVSS 5.1 Medium.

Data as of 26 Oct 2026, 08:30 UTC

CVSS 3.1 base score

5.1Medium

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

EPSS: 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

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

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

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: High: The attacker is authorized with (i.e., requires) privileges that provide significant (e.g., administrative) control over the vulnerable component that could affect component-wide settings and files.
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: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 11 Jul 2025
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: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

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

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

Affected software

Product	Affected	Fixed in
Juniper Networks Junos OS	Affected =0 =22.4 =23.2 =23.4 =24.2 =24.4	Fixed in–

AI-suggested

To mitigate this vulnerability effectively, European organizations should: 1) Immediately identify and inventory all Junos OS and Junos OS Evolved devices within their networks to assess exposure. 2) Apply the latest Juniper patches and updates corresponding to the affected versions as soon as they become available, prioritizing devices in critical network segments. 3) Restrict high-privilege access strictly to trusted personnel and implement robust multi-factor authentication (MFA) to reduce the risk of credential compromise. 4) Monitor configuration change logs and audit trails for unusual or unauthorized 'annotate' commands or configuration modifications, employing automated alerting where possible. 5) Employ network segmentation to limit access to management interfaces, ensuring that only authorized management stations can connect to Junos devices. 6) Conduct regular security training for administrators to recognize and report suspicious activities. 7) Consider deploying configuration integrity monitoring tools that can detect unauthorized changes promptly. These steps go beyond generic advice by focusing on access control hardening, proactive monitoring, and rapid patch deployment tailored to the nature of this vulnerability.

Description

An Improper Neutralization of Delimiters vulnerability in the UI of Juniper Networks Junos OS and Junos OS Evolved allows a local, authenticated attacker with high privileges to modify the system configuration. A user with limited configuration and commit permissions, using a specifically crafted annotate configuration command, can change any part of the device configuration. This issue affects: Junos OS: * all versions before 22.2R3-S7, * 22.4 versions before 22.4R3-S7, * 23.2 versions before 23.2R2-S4, * 23.4 versions before 23.4R2-S4, * 24.2 versions before 24.2R2-S1, * 24.4 versions before 24.4R1-S2, 24.4R2; Junos OS Evolved: * all versions before 22.4R3-S7-EVO, * 23.2-EVO versions before 23.2R2-S4-EVO, * 23.4-EVO versions before 23.4R2-S5-EVO, * 24.2-EVO versions before 24.2R2-S1-EVO * 24.4-EVO versions before 24.4R2-EVO.

Impact

For European organizations, the impact of this vulnerability is significant in environments relying on Juniper Networks' Junos OS devices, which are commonly used in enterprise and service provider networks across Europe. Unauthorized configuration changes can lead to network outages, misrouting, exposure of sensitive data, or introduction of backdoors, severely affecting the integrity and availability of network infrastructure. Given that the vulnerability requires local authenticated access with high privileges, the risk is primarily from insider threats or attackers who have already compromised administrative credentials. However, once exploited, it can facilitate persistent and stealthy manipulation of network devices, complicating incident response and remediation efforts. This can disrupt critical services, especially in sectors such as finance, telecommunications, and government, where network reliability and security are paramount. Additionally, the lack of confidentiality impact reduces the risk of direct data leakage but does not mitigate the threat to network integrity and availability.

CWE-140Improper Neutralization of Delimiters (opens in a new tab)
Base weakness
The product does not neutralize or incorrectly neutralizes delimiters.
Implementation · Input Validation
Developers should anticipate that delimiters will be injected/removed/manipulated in the input vectors of their product. Use an appropriate combination of denylists and allowlists to ensure only valid, expected and appropriate input is processed by the system.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
Implementation · Output Encoding
While it is risky to use dynamically-generated query strings, code, or commands that mix control and data together, sometimes it may be unavoidable. Properly quote arguments and escape any special characters within those arguments.
OWASP Cheat Sheets
Abuse Case (opens in a new tab)
Deserialization (opens in a new tab)
Server Side Request Forgery Prevention (opens in a new tab)
Unvalidated Redirects and Forwards (opens in a new tab)
Cross Site Scripting Prevention (opens in a new tab)
OWASP ASVS 4.0.3
V1.5.1 (opens in a new tab)
V5.2.2 (opens in a new tab)
Attack patterns
Command Delimiters (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

supportportal.juniper.net/JSA100096 (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 25 Sep 2025, 00:18 UTC

WeaknessesCWE-140

Technical details

References

Community reviews

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