Input validation error in Junos OS and Junos OS Evolved - CVE-2021-0211

Vulnerability identifier: #VU49553

CSH Severity: Medium

CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2021-0211

CWE-ID: CWE-20

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to insufficient validation of user-supplied input when processing BGP mesages. A remote attacker can send a valid BGP FlowSpec message and perform a denial of service (DoS) attack.

Junos OS
Junos OS Evolved

Install updates from vendor's website.

Junos OS - addressed in versions 15.1X49-D240, 17.3R3-S10, 17.4R2-S12, 17.4R3-S4, 18.1R3-S12, 18.2R2-S8, 18.2R3-S6, 18.3R3-S4, 18.4R1-S8, 18.4R2-S6, 18.4R3-S6, 19.1R2-S2, 19.1R3-S3, 19.2R3-S1, 19.3R2-S5, 19.3R3-S1, 19.4R1-S3, 19.4R2-S3, 19.4R3, 20.1R2, 20.2R1-S3, 20.2R2, 20.3R1-S1, 20.3R2, 20.4R1
Junos OS Evolved - addressed in versions 20.3R1-S1-EVO, 20.3R2-EVO, 20.4R1-EVO

• https://kb.juniper.net/InfoCenter/index?page=content&id=JSA11101&cat=SIRT_1&actp=LIST

• Denial of service when processing BGP messages in Junos OS and Junos OS Evolved