CVE-2021-0246

CVE-2021-0246 is a high-severity vulnerability in Juniper Junos with a CVSS 3.x base score of 7.3. 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-276.

Key facts

Description

On SRX1500, SRX4100, SRX4200, SRX4600, SRX5000 Series with SPC2/SPC3, devices using tenant services on Juniper Networks Junos OS, due to incorrect default permissions assigned to tenant system administrators a tenant system administrator may inadvertently send their network traffic to one or more tenants while concurrently modifying the overall device system traffic management, affecting all tenants and the service provider. Further, a tenant may inadvertently receive traffic from another tenant. This issue affects: Juniper Networks Junos OS 18.3 version 18.3R1 and later versions on SRX1500, SRX4100, SRX4200, SRX4600, SRX5000 Series with SPC2; 18.3 versions prior to 18.3R3 on SRX1500, SRX4100, SRX4200, SRX4600, SRX5000 Series with SPC2; 18.4 versions prior to 18.4R2 on SRX1500, SRX4100, SRX4200, SRX4600, SRX5000 Series with SPC2/SPC3; 19.1 versions prior to 19.1R2 on SRX1500, SRX4100, SRX4200, SRX4600, SRX5000 Series with SPC2/SPC3. This issue does not affect: Juniper Networks Junos OS versions prior to 18.3R1.

Frequently asked questions

What is CVE-2021-0246?
On SRX1500, SRX4100, SRX4200, SRX4600, SRX5000 Series with SPC2/SPC3, devices using tenant services on Juniper Networks Junos OS, due to incorrect default permissions assigned to tenant system administrators a tenant system administrator may inadvertently send their network traffic to one or more tenants while concurrently modifying the overall device system traffic management, affecting all tenants and the service provider. Further, a tenant may inadvertently receive traffic from another tenant. This issue affects: Juniper Networks Junos OS 18.3 version 18.3R1 and later versions on SRX1500, SRX4100, SRX4200, SRX4600, SRX5000 Series with SPC2; 18.3 versions prior to 18.3R3 on SRX1500, SRX4100, SRX4200, SRX4600, SRX5000 Series with SPC2; 18.4 versions prior to 18.4R2 on SRX1500, SRX4100, SRX4200, SRX4600, SRX5000 Series with SPC2/SPC3; 19.1 versions prior to 19.1R2 on SRX1500, SRX4100, SRX4200, SRX4600, SRX5000 Series with SPC2/SPC3. This issue does not affect: Juniper Networks Junos OS versions prior to 18.3R1.
How severe is CVE-2021-0246?
CVE-2021-0246 has a CVSS 3.x base score of 7.3, rated high severity. It is exploitable over local access with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is low, integrity high, and availability low.
Is CVE-2021-0246 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (15th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-0246?
CVE-2021-0246 primarily affects Juniper Junos. In total, 29 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-0246?
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.
When was CVE-2021-0246 published?
CVE-2021-0246 was published on 2021-04-22 and last updated on 2026-06-17.

References

Affected products (29)

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