Cyber Resilience

CVE-2024-39559

High

Published: 10 July 2024

Published
10 July 2024
Modified
07 February 2025
KEV Added
Patch
CVSS Score v4 8.2 CVSS:4.0/AV:N/AC:L/AT:P/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:A/V:X/RE:X/U:X
EPSS Score 0.0042 62.4th percentile
Risk Priority 17 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2024-39559 is a high-severity Improper Check for Unusual or Exceptional Conditions (CWE-754) vulnerability in Juniper Junos Os Evolved. Its CVSS base score is 8.2 (High).

Operationally, ranked in the top 37.6% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

An Improper Check for Unusual or Exceptional Conditions vulnerability in packet processing of Juniper Networks Junos OS Evolved may allow a network-based unauthenticated attacker to crash the device (vmcore) by sending a specific TCP packet over an established TCP session…

more

with MD5 authentication enabled, destined to an accessible port on the device, resulting in a Denial of Service (DoS). The receipt of this packet must occur within a specific timing window outside the attacker's control (i.e., race condition). Continued receipt and processing of this packet will create a sustained Denial of Service (DoS) condition. This issue only affects dual RE systems with Nonstop Active Routing (NSR) enabled. Exploitation can only occur over TCP sessions with MD5 authentication enabled (e.g., BGP with MD5 authentication). This issue affects Junos OS Evolved: * All versions before 21.2R3-S8-EVO, * from 21.4-EVO before 21.4R3-S6-EVO, * from 22.1-EVO before 22.1R3-S4-EVO, * from 22.2-EVO before 22.2R3-S4-EVO, * from 22.3-EVO before 22.3R3-S3-EVO, * from 22.4-EVO before 22.4R2-S2-EVO, 22.4R3-EVO.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

juniper
junos os evolved
21.2, 21.4, 22.1, 22.2, 22.3 · ≤ 21.2

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-754

Requires detection and response to audit logging failures as an unusual or exceptional condition.

addresses: CWE-754

Implements detection of unusual or exceptional conditions followed by safe mode entry, reducing the window for exploitation of unchecked conditions.

addresses: CWE-754

Training ensures users perform required checks for unusual or exceptional conditions as part of contingency roles, limiting attacker leverage from skipped validations.

addresses: CWE-754

IR testing directly validates checks for unusual or exceptional conditions that could indicate security incidents.

addresses: CWE-754

Requires ongoing monitoring of organization-defined metrics and analysis, enabling checks for unusual or exceptional conditions.

addresses: CWE-754

Security testing routinely checks for unusual or exceptional inputs/conditions, identifying missing validation steps that flaw remediation then resolves.

addresses: CWE-754

Requires detection of unusual conditions followed by a controlled transition to the defined failure state.

addresses: CWE-754

MTTF determination forces explicit checks for conditions that precede predictable component failure.

References