Cyber Resilience

CVE-2025-30651

Juniper Junos ≤ 21.2

Published
09 April 2025
Modified
23 January 2026
Patch / advisory
View advisory
CVSS Score v4 8.7
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0040 33th percentile
Risk Priority 44 floored blend · peak EPSS

Summary

CVE-2025-30651 is a high-severity Buffer Access with Incorrect Length Value (CWE-805) vulnerability in Juniper Junos. Its CVSS base score is 8.7 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 33th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

A Buffer Access with Incorrect Length Value vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, network-based attacker to cause a Denial of Service (DoS). When an attacker sends a…

more

specific ICMPv6 packet to an interface with "protocols router-advertisement" configured, rpd crashes and restarts. Continued receipt of this packet will cause a sustained DoS condition. This issue only affects systems configured with IPv6. 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-S4, * from 23.2 before 23.2R2-S2, * from 23.4 before 23.4R2; and Junos OS Evolved: * All versions before 21.2R3-S9-EVO, * from 21.4-EVO before 21.4R3-S10-EVO, * from 22.2-EVO before 22.2R3-S6-EVO, * from 22.4-EVO before 22.4R3-S4-EVO, * from 23.2-EVO before 23.2R2-S2-EVO, * from 23.4-EVO before 23.4R2-EVO.

CWE(s)
CWE-805

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
attack.mitre.org →
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-30386Same product: Juniper Junos
CVE-2024-30395Same product: Juniper Junos
CVE-2026-21921Same product: Juniper Junos
CVE-2025-30646Same product: Juniper Junos
CVE-2025-21591Same product: Juniper Junos
CVE-2024-39543Same product: Juniper Junos
CVE-2023-44182Same product: Juniper Junos
CVE-2024-39558Same product: Juniper Junos
CVE-2025-30653Same product: Juniper Junos
CVE-2025-52955Same product: Juniper Junos

Affected Assets

juniper
junos
21.2, 21.4, 22.2, 22.4, 23.2 · ≤ 21.2
juniper
junos os evolved
21.2, 21.4, 22.2, 22.4, 23.2 · ≤ 21.2

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V1.4.1

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation (including fuzzing and static analysis) directly finds incorrect length values used in sequential buffer accesses.

SA-8 Security and Privacy Engineering Principles partial match

Secure engineering principles require explicit bounds checking and correct length calculations when performing buffer operations.

SI-10 Information Input Validation partial match

Input validation rejects or corrects malformed length values supplied from external sources before they reach buffer operations.

SI-16 Memory Protection partial match

Memory protection mechanisms limit the blast radius when an incorrect length value causes an out-of-bounds access.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly prevent incorrect-length buffer operations via safe APIs, reviews, and testing.

ID.RA-01 partial match
prevents

Vulnerability identification can discover buffer-length flaws but does not prevent their introduction.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing in development can detect out-of-bounds accesses, but does not guarantee prevention.

A.8.25 Secure development life cycle partial match
prevents

Secure development life cycle mandates buffer-safety practices that directly prevent incorrect length values.

A.8.26 Application security requirements partial match
prevents

Application security requirements can specify buffer-size validation, but do not prescribe implementation details.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture principles encourage bounds-checked APIs, yet leave concrete coding decisions to developers.

A.8.28 Secure coding partial match
prevents

Secure coding explicitly requires correct buffer-length handling, eliminating CWE-805 when followed.

References