This issue affects Junos OS 15.1, 15.1X49, 17.3, 17.4, 18.1, 18.2, 18.3, 18.4, 19.1, 19.2, 19.3, 19.4, 20.1, 20.2, 20.3. This issue affects Junos OS Evolved 20.3.
An improper check for unusual or exceptional conditions in Juniper Networks Junos OS and Junos OS Evolved Routing Protocol Daemon (RPD) service allows an attacker to send a valid BGP FlowSpec message thereby causing an unexpected change in the route advertisements within the BGP FlowSpec domain leading to disruptions in network traffic causing a Denial of Service (DoS) condition.
Continued receipt of these update messages will cause a sustained Denial of Service condition.
This issue affects Juniper Networks:
Junos OS:
- All versions prior to 17.3R3-S10 with the exceptions of 15.1X49-D240 on SRX Series and 15.1R7-S8 on EX Series;
- 17.4 versions prior to 17.4R2-S12, 17.4R3-S4;
- 18.1 versions prior to 18.1R3-S12;
- 18.2 versions prior to 18.2R2-S8, 18.2R3-S6;
- 18.3 versions prior to 18.3R3-S4;
- 18.4 versions prior to 18.4R1-S8, 18.4R2-S6, 18.4R3-S6;
- 19.1 versions prior to 19.1R1-S6, 19.1R2-S2, 19.1R3-S3;
- 19.2 versions prior to 19.2R3-S1;
- 19.3 versions prior to 19.3R2-S5, 19.3R3-S1;
- 19.4 versions prior to 19.4R1-S3, 19.4R2-S3, 19.4R3;
- 20.1 versions prior to 20.1R2;
- 20.2 versions prior to 20.2R1-S3 20.2R2;
- 20.3 versions prior to 20.3R1-S1, 20.3R2.
Junos OS Evolved:
- All versions prior to 20.3R1-S1-EVO, 20.3R2-EVO.
The following minimal configuration is required to potentially hit this issue:
protocols bgp family inet flow
Juniper SIRT is not aware of any malicious exploitation of this vulnerability.
This issue was seen during production usage.
This issue has been assigned CVE-2021-0211.
The following software releases have been updated to resolve this specific issue:
Junos OS: 15.1R7-S8, 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, and all subsequent releases.
Junos OS Evolved: 20.3R1-S1-EVO, 20.3R2-EVO, 20.4R1-EVO, and all subsequent releases.
This issue is being tracked as 1539109.
There are no viable workarounds for this issue.
Software releases or updates are available for download at
https://www.juniper.net/support/downloads/.
Information for how Juniper Networks uses CVSS can be found at KB 16446 "Common Vulnerability Scoring System (CVSS) and Juniper's Security Advisories."