CVE-2021-0209

CVE-2021-0209 is a medium-severity vulnerability in Juniper Junos Os Evolved with a CVSS 3.x base score of 6.5. 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-824.

Key facts

Description

In Juniper Networks Junos OS Evolved an attacker sending certain valid BGP update packets may cause Junos OS Evolved to access an uninitialized pointer causing RPD to core leading to a Denial of Service (DoS). Continued receipt of these types of valid BGP update packets will cause an extended Denial of Service condition. RPD will require a restart to recover. An indicator of compromise is to see if the file rpd.re exists by issuing the command: show system core-dumps This issue affects: Juniper Networks Junos OS Evolved 19.4 versions prior to 19.4R2-S2-EVO; 20.1 versions prior to 20.1R1-S2-EVO, 20.1R2-S1-EVO. This issue does not affect Junos OS.

Frequently asked questions

What is CVE-2021-0209?
In Juniper Networks Junos OS Evolved an attacker sending certain valid BGP update packets may cause Junos OS Evolved to access an uninitialized pointer causing RPD to core leading to a Denial of Service (DoS). Continued receipt of these types of valid BGP update packets will cause an extended Denial of Service condition. RPD will require a restart to recover. An indicator of compromise is to see if the file rpd.re exists by issuing the command: show system core-dumps This issue affects: Juniper Networks Junos OS Evolved 19.4 versions prior to 19.4R2-S2-EVO; 20.1 versions prior to 20.1R1-S2-EVO, 20.1R2-S1-EVO. This issue does not affect Junos OS.
How severe is CVE-2021-0209?
CVE-2021-0209 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-0209 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (35th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-0209?
CVE-2021-0209 primarily affects Juniper Junos Os Evolved. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-0209?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-0209 published?
CVE-2021-0209 was published on 2021-01-15 and last updated on 2026-06-17.

References

Affected products (6)

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