Main Vulnerability Database Vulnerabilities #VU52286

Improper Check for Unusual or Exceptional Conditions in Junos OS and Junos OS Evolved - CVE-2021-0236

Published: April 16, 2021

Vulnerability identifier: #VU52286

CSH Severity: Medium

CVSS v4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2021-0236

CWE-ID: CWE-754

Exploitation vector: Remote access

Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a remote user to perform denial of service attack.

The vulnerability exists due to improper check for unusual or exceptional conditions within the Routing Protocol Daemon (RPD) service when handling BGP VPNv6 flowspec messages. A remote user attacker can send specific matching BGP packet, which meets a specific term in the flowspec configuration and crash the service.

Affected software

Junos OS
Junos OS Evolved

How to mitigate CVE-2021-0236

Install updates from vendor's website.

Junos OS - addressed in versions 18.4R1-S8, 18.4R2-S7, 18.4R3-S7, 19.1R2-S2, 19.1R3-S4, 19.2R1-S6, 19.2R3-S2, 19.3R3-S2, 19.4R2-S4, 19.4R3-S1, 20.1R2, 20.1R3, 20.2R2, 20.2R3, 20.3R1-S1, 20.3R2, 20.4R1
Junos OS Evolved - addressed in versions 20.3R2-EVO, 20.4R1-EVO

External References

https://kb.juniper.net/InfoCenter/index?page=content&id=JSA11131&cat=SIRT_1&actp=LIST

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