CVE-2024-21586

CVE-2024-21586 is a high-severity vulnerability in Juniper Junos with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-754.

Key facts

Description

An Improper Check for Unusual or Exceptional Conditions vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on SRX Series and NFX Series allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS). If an affected device receives specific valid traffic destined to the device, it will cause the PFE to crash and restart. Continued receipt and processing of this traffic will create a sustained DoS condition. This issue affects Junos OS on SRX Series: * 21.4 versions before 21.4R3-S7.9, * 22.1 versions before 22.1R3-S5.3, * 22.2 versions before 22.2R3-S4.11, * 22.3 versions before 22.3R3, * 22.4 versions before 22.4R3. This issue affects Junos OS on NFX Series: * 21.4 versions before 21.4R3-S8, * 22.1 versions after 22.1R1, * 22.2 versions before 22.2R3-S5, * 22.3 versions before 22.3R3, * 22.4 versions before 22.4R3. Junos OS versions prior to 21.4R1 are not affected by this issue.

Frequently asked questions

What is CVE-2024-21586?
An Improper Check for Unusual or Exceptional Conditions vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on SRX Series and NFX Series allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS). If an affected device receives specific valid traffic destined to the device, it will cause the PFE to crash and restart. Continued receipt and processing of this traffic will create a sustained DoS condition. This issue affects Junos OS on SRX Series: * 21.4 versions before 21.4R3-S7.9, * 22.1 versions before 22.1R3-S5.3, * 22.2 versions before 22.2R3-S4.11, * 22.3 versions before 22.3R3, * 22.4 versions before 22.4R3. This issue affects Junos OS on NFX Series: * 21.4 versions before 21.4R3-S8, * 22.1 versions after 22.1R1, * 22.2 versions before 22.2R3-S5, * 22.3 versions before 22.3R3, * 22.4 versions before 22.4R3. Junos OS versions prior to 21.4R1 are not affected by this issue.
How severe is CVE-2024-21586?
CVE-2024-21586 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2024-21586 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (39th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2024-21586?
CVE-2024-21586 primarily affects Juniper Junos. In total, 54 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2024-21586?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2024-21586 have an EU (EUVD) identifier?
Yes. CVE-2024-21586 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-19234.
When was CVE-2024-21586 published?
CVE-2024-21586 was published on 2024-07-01 and last updated on 2026-06-17.

References

Affected products (54)

More vulnerabilities in Juniper Junos

All CVEs affecting Juniper Junos →

Other CWE-754 (Improper Check for Unusual or Exceptional Conditions) vulnerabilities

Browse all CWE-754 (Improper Check for Unusual or Exceptional Conditions) vulnerabilities →