CVE-2024-21607
Juniper Junos ≤ 20.4
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:NCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2024-21607 is a medium-severity Unimplemented or Unsupported Feature in UI (CWE-447) vulnerability in Juniper Junos. Its CVSS base score is 5.3 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Junk Data (T1001.001); ranked at the 22th 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 SI-6 (Security and Privacy Function Verification) — see the control section below for these in your framework.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2024-19255
Vulnerability Data
An Unsupported Feature in the UI vulnerability in Juniper Networks Junos OS on MX Series and EX9200 Series allows an unauthenticated, network-based attacker to cause partial impact to the integrity of the device. If the "tcp-reset" option is added to…
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the "reject" action in an IPv6 filter which matches on "payload-protocol", packets are permitted instead of rejected. This happens because the payload-protocol match criteria is not supported in the kernel filter causing it to accept all packets without taking any other action. As a fix the payload-protocol match will be treated the same as a "next-header" match to avoid this filter bypass. This issue doesn't affect IPv4 firewall filters. This issue affects Juniper Networks Junos OS on MX Series and EX9200 Series: * All versions earlier than 20.4R3-S7; * 21.1 versions earlier than 21.1R3-S5; * 21.2 versions earlier than 21.2R3-S5; * 21.3 versions earlier than 21.3R3-S4; * 21.4 versions earlier than 21.4R3-S4; * 22.1 versions earlier than 22.1R3-S2; * 22.2 versions earlier than 22.2R3-S2; * 22.3 versions earlier than 22.3R2-S2, 22.3R3; * 22.4 versions earlier than 22.4R1-S2, 22.4R2-S2, 22.4R3.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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- 1 hardening rule · 1 OS baseline
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Mitigating Controls (NIST 800-53 r5) AI
Developer testing at post-design stages directly exercises UI claims versus actual behavior and will expose unimplemented security features.
Periodic verification of security functions will reveal that a UI-advertised capability is not actually present or operating.
Requiring a documented development process and tools reduces the chance that a security feature is left unimplemented while its UI is shipped.
Mandating an SDLC that incorporates security engineering makes it less likely that advertised features remain stubs.
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.
Security tests and exercises would detect unimplemented UI features, though the control addresses broader improvement identification.
Secure SDLC practices and monitoring directly prevent stubbed security features by requiring verified implementation and testing.
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.
Secure development lifecycle requires that security features are actually implemented, not just presented in the UI.
A.8.26 only requires that security requirements (including resilience against attacks such as SQL injection) be identified and specified during development or acquisition; it does not itself enforce, implement or prevent the UI-misleading defect named by CWE-447 from being introduced or exploited.
Secure coding practices reduce the chance of leaving security features unimplemented.
Security testing in development and acceptance would detect unimplemented security features before release.