This issue affects all versions of Junos OS. Affected platforms: QFX10K Series.
In an EVPN/VXLAN scenario, if an IRB interface with a virtual gateway address (VGA) is configured on a PE, a traffic loop may occur upon receipt of specific IP multicast traffic. The traffic loop will cause interface traffic to increase abnormally, ultimately leading to a Denial of Service (DoS) in packet processing.
The following command could be used to monitor the interface traffic:
user@junos> monitor interface traffic
Interface Link Input packets (pps) Output packets (pps)
et-0/0/1 Up 6492089274364 (70994959) 6492089235319 (70994956)
et-0/0/25 Up 343458103 (1) 156844 (0)
ae0 Up 9132519197257 (70994959) 9132519139454 (70994956)
This issue affects Juniper Networks Junos OS on QFX10K Series:
- all versions prior to 17.3R3-S10;
- 17.4 versions prior to 17.4R2-S12, 17.4R3-S3;
- 18.1 versions prior to 18.1R3-S11;
- 18.2 versions prior to 18.2R3-S6;
- 18.3 versions prior to 18.3R3-S4;
- 18.4 versions prior to 18.4R2-S5, 18.4R3-S5;
- 19.1 versions prior to 19.1R1-S6, 19.1R2-S2, 19.1R3-S3;
- 19.2 versions prior to 19.2R1-S5, 19.2R3-S1;
- 19.3 versions prior to 19.3R2-S5, 19.3R3;
- 19.4 versions prior to 19.4R2-S2, 19.4R3;
- 20.1 versions prior to 20.1R2;
- 20.2 versions prior to 20.2R1-S2, 20.2R2.
This issue only affects the QFX10K Series (QFX10002, QFX10008). No other products or platforms are affected by this vulnerability.
A sample IRB configuration using virtual gateway addresses is shown below:
user@junos# show interfaces irb.1162
virtual-gateway-accept-data;
family inet {
address 192.168.190.125/25 {
virtual-gateway-address 192.168.190.1;
}
address 192.168.190.253/25 {
virtual-gateway-address 192.168.190.129;
}
}
virtual-gateway-v4-mac 00:08:2b:03:05:07;
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-2021-0221.
The following software releases have been updated to resolve this specific issue: Junos OS 17.3R3-S10, 17.4R2-S12, 17.4R3-S3, 18.1R3-S11, 18.2R3-S6, 18.3R3-S4, 18.4R2-S5, 18.4R3-S5, 19.1R1-S6, 19.1R2-S2, 19.1R3-S3, 19.2R1-S5, 19.2R3-S1, 19.3R2-S5, 19.3R3, 19.4R2-S2, 19.4R3, 20.1R2, 20.2R1-S2, 20.2R2, 20.3R1, and all subsequent releases.
This issue is being tracked as 1518537.
Software releases or updates are available for download at
https://www.juniper.net/support/downloads/.
2021-01-13: Initial Publication.
2021-01-19: Clarified that the issue only affects QFX10K Series switches.
Information for how Juniper Networks uses CVSS can be found at KB 16446 "Common Vulnerability Scoring System (CVSS) and Juniper's Security Advisories."