Cyber Resilience

CVE-2025-30656

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:Y/R:A/V:X/RE:M/U:X
EPSS Score 0.0040 33th percentile
Risk Priority 45 floored blend · peak EPSS

Summary

CVE-2025-30656 is a high-severity Improper Handling of Additional Special Element (CWE-167) vulnerability in Juniper Junos. Its CVSS base score is 8.7 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); 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 SI-10 (Information Input Validation) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

An Improper Handling of Additional Special Element vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on MX Series with MS-MPC, MS-MIC and SPC3, and SRX Series, allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS).…

more

If the SIP ALG processes specifically formatted SIP invites, a memory corruption will occur which will lead to a crash of the FPC processing these packets. Although the system will automatically recover with the restart of the FPC, subsequent SIP invites will cause the crash again and lead to a sustained DoS. This issue affects Junos OS on MX Series and SRX Series: * all versions before 21.2R3-S9, * 21.4 versions before 21.4R3-S10, * 22.2 versions before 22.2R3-S6, * 22.4 versions before 22.4R3-S5, * 23.2 versions before 23.2R2-S3, * 23.4 versions before 23.4R2-S3, * 24.2 versions before 24.2R1-S2, 24.2R2.

CWE(s)
CWE-167

Related Threats

MITRE ATT&CK Enterprise Techniques

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 →
T1059 Command and Scripting Interpreter Execution
Adversaries may abuse command and script interpreters to execute commands, scripts, or binaries.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1659 Content Injection Initial Access
Adversaries may gain access and continuously communicate with victims by injecting malicious content into systems through online network traffic.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-52960Same product: Juniper Junos
CVE-2026-21918Same product: Juniper Junos
CVE-2026-33778Same product: Juniper Junos
CVE-2026-21905Same product: Juniper Junos
CVE-2024-39545Same product: Juniper Junos
CVE-2024-39551Same product: Juniper Junos
CVE-2023-44198Same product: Juniper Junos
CVE-2025-30659Same product: Juniper Junos
CVE-2026-57023Same product: Juniper Junos
CVE-2026-57026Same product: Juniper Junos

Affected Assets

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

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

SI-10 Information Input Validation partial match

SI-10 requires validity checks on inputs that directly stop additional unexpected special elements from being mishandled.

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 require correct input parsing and special-element handling during development.

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 catches improper handling of unexpected special elements before release.

A.8.25 Secure development life cycle partial match
prevents

Secure development lifecycle mandates input validation and handling of unexpected data elements.

A.8.26 Application security requirements partial match
prevents

Application security requirements explicitly call for robust input validation against malformed or special-element data.

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

Secure architecture principles include defensive input handling to prevent injection or parsing anomalies.

A.8.28 Secure coding partial match
prevents

Secure coding standards directly require correct handling of all input elements, eliminating this weakness.

References