An Improper Input Validation vulnerability in the Juniper DHCP Daemon (jdhcpd) of Juniper…
CVE-2025-30648 is a high-severity improper input validation vulnerability in Junos OS from Juniper Networks, with a CVSS 3.1 base score of 7.4 out of 10. It can be exploited from the same local network by an unauthenticated attacker, without any action from a user. The record lists versions 21.2R3-S9, 21.4R3-S10, 22.2R3-S6 as the first without the flaw, so updating Junos OS to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.24% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Junos OS to 21.2R3-S9 or 21.4R3-S10 or 22.2R3-S6 or 22.4R3-S6, whichever matches your release line, or a later version.
- Update Junos OS Evolved to 22.4R3-S6-EVO or 23.2R2-S3-EVO or 23.4R2-S4-EVO or 24.2R2-EVO, whichever matches your release line, or a later version.
- Update Junos to 21.2 or a later version.
- Read the advisory on supportportal.juniper.net for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Juniper Networks | Junos OS | before 21.2R3-S9; 21.4 up to, but not including, 21.4R3-S10; 22.2 up to, but not including, 22.2R3-S6; 22.4 up to, but not including, 22.4R3-S6; 23.2 up to, but not including, 23.2R2-S3; 23.4 up to, but not including, 23.4R2-S4; 24.2 up to, but not including, 24.2R2 | 21.2R3-S9, 21.4R3-S10, 22.2R3-S6, 22.4R3-S6, 23.2R2-S3, 23.4R2-S4 |
| Juniper Networks | Junos OS Evolved | 22.4 up to, but not including, 22.4R3-S6-EVO; 23.2 up to, but not including, 23.2R2-S3-EVO; 23.4 up to, but not including, 23.4R2-S4-EVO; 24.2 up to, but not including, 24.2R2-EVO | 22.4R3-S6-EVO, 23.2R2-S3-EVO, 23.4R2-S4-EVO, 24.2R2-EVO |
| Juniper Networks | Junos | before 21.2; 21.2; 21.4; 22.2; 22.4; 23.2; 23.4; 24.2 | 21.2 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- AdjacentThe attacker must be on the same local network segment.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H. Scored by CNA (juniper.net).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 7.1 | High | CNA (juniper.net) |
| CVSS 3.1 | 7.4 | High | CNA (juniper.net) |
Official description
An Improper Input Validation vulnerability in the Juniper DHCP Daemon (jdhcpd) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, adjacent attacker to cause the jdhcpd process to crash resulting in a Denial of Service (DoS). When a specifically malformed DHCP packet is received from a DHCP client, the jdhcpd process crashes, which will lead to the unavailability of the DHCP service and thereby resulting in a sustained DoS. The DHCP process will restart automatically to recover the service. This issue will occur when dhcp-security is enabled. This issue affects Junos OS: * All versions before 21.2R3-S9, * from 21.4 before 21.4R3-S10, * from 22.2 before 22.2R3-S6, * from 22.4 before 22.4R3-S6, * from 23.2 before 23.2R2-S3, * from 23.4 before 23.4R2-S4, * from 24.2 before 24.2R2; Junos OS Evolved: * from 22.4 before 22.4R3-S6-EVO, * from 23.2 before 23.2R2-S3-EVO, * from 23.4 before 23.4R2-S4-EVO, * from 24.2 before 24.2R2-EVO. .
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Input Validation
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
How developers prevent this class of flaw
- Consider using language-theoretic security (LangSec) techniques that characterize inputs using a formal language and build recognizers for that language. This effectively requires parsing to be a distinct layer that effectively enforces a boundary between raw input and internal data representations, instead of allowing parser code to be scattered throughout the program, where it could be subject to errors or inconsistencies that create weaknesses.
- Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
- Understand all the potential areas where untrusted inputs can enter the product, including but not limited to: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly through API calls.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Other vulnerabilities in Junos OS
- 7.5 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 8.8 High severity
- 8.8 High severity
- 7.5 High severity
Recent Improper Input Validation vulnerabilities
- 7.5 High severity
- 7.8 High severity
- 9.1 Critical severity
- 7.5 High severity
- 8.8 High severity
- 9.8 Critical severity
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