CVE-2025-52953
Juniper Junos ≤ 21.2
Raw vector
CVSS:4.0/AV:A/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:C/RE:M/U:AmberSummary
CVE-2025-52953 is a high-severity Expected Behavior Violation (CWE-440) vulnerability in Juniper Junos. Its CVSS base score is 7.1 (High).
Operationally, ranked at the 20th 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.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-21156
Vulnerability Data
An Expected Behavior Violation vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated adjacent attacker sending a valid BGP UPDATE packet to cause a BGP session reset, resulting in a…
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Denial of Service (DoS). Continuous receipt and processing of this packet will create a sustained Denial of Service (DoS) condition. This issue affects iBGP and eBGP and both IPv4 and IPv6 are affected by this vulnerability. This issue affects Junos OS: * All versions before 21.2R3-S9, * from 21.4 before 21.4R3-S11, * from 22.2 before 22.2R3-S7, * from 22.4 before 22.4R3-S7, * from 23.2 before 23.2R2-S4, * from 23.4 before 23.4R2-S4, * from 24.2 before 24.2R2, * from 24.4 before 24.4R1-S3, 24.4R2 Junos OS Evolved: * All versions before 22.2R3-S7-EVO, * from 22.4-EVO before 22.4R3-S7-EVO, * from 23.2-EVO before 23.2R2-S4-EVO, * from 23.4-EVO before 23.4R2-S4-EVO, * from 24.2-EVO before 24.2R2-EVO, * from 24.4-EVO before 24.4R1-S3-EVO, 24.4R2-EVO.
- CWE(s)
Related Threats
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation directly checks whether implemented functions match their specifications.
Security function verification confirms that functions operate according to their defined expected behavior.
Requiring a documented security architecture and design reduces the chance that implementation deviates from intended behavior.
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.
Secure SDLC practices directly enforce specification compliance and catch expected-behavior violations during development.
Security testing and exercises help discover behavior deviations before deployment.
Vulnerability identification can surface spec-violating flaws, while eliminating the weakness reduces some vulnerability backlog.
Routine software maintenance and patching can remediate discovered specification violations.
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.
Security testing in development and acceptance validates that functions behave as specified.
Secure development life cycle mandates verification against specifications, directly reducing expected-behavior violations.
Application security requirements explicitly define expected behavior that must be met.
Secure coding practices enforce adherence to functional specifications during implementation.
Change management can catch specification deviations introduced by modifications.
Documented operating procedures reduce the chance that functions deviate from intended behavior.