CVE-2025-21591
7.4 · HIGHOverview
CVE-2025-21591 is a high-severity vulnerability affecting juniper junos. It was published on April 9, 2025 and has a CVSS 3.1 base score of 7.4 (HIGH).
This vulnerability has a CVSS 3.1 base score of 7.4, rated HIGH. It requires local or adjacent network access to exploit. No authentication or special privileges are required for exploitation.
Technical Description
A Buffer Access with Incorrect Length Value vulnerability in the jdhcpd daemon of Juniper Networks Junos OS, when DHCP snooping is enabled, allows an unauthenticated, adjacent, attacker to send a DHCP packet with a malformed DHCP option to cause jdhcp to crash creating a Denial of Service (DoS) condition.
Continuous receipt of these DHCP packets using the malformed DHCP Option will create a sustained Denial of Service (DoS) condition.
This issue affects Junos OS:
* from 23.1 before 23.2R2-S3,
* from 23.4 before 23.4R2-S3,
* from 24.2 before 24.2R2.
This issue isn't applicable to any versions of Junos OS before 23.1R1.
This issue doesn't affect vSRX Series which doesn't support DHCP Snooping.
This issue doesn't affect Junos OS Evolved.
There are no indicators of compromise for this issue.
Remediation
Check the references section for vendor advisories and patches from juniper. Update junos to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|
References
Frequently Asked Questions
What is CVE-2025-21591?
CVE-2025-21591 is a high-severity vulnerability affecting juniper junos. It was published on April 9, 2025 and has a CVSS 3.1 base score of 7.4 (HIGH).
How severe is CVE-2025-21591?
This vulnerability has a CVSS 3.1 base score of 7.4, rated HIGH. It requires local or adjacent network access to exploit. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2025-21591?
Check the references section for vendor advisories and patches from juniper. Update junos to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2025-21591?
CyberStrike's AI-powered security agents can automatically detect CVE-2025-21591 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
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