CVE-2021-0244

Vulnerability Summary

A signal handler race condition exists in the Layer 2 Address Learning Daemon (L2ALD) of Juniper Networks Junos OS due to the absence of a specific protection mechanism to avoid a race condition which may allow an malicious user to bypass the storm-control feature on devices. This issue is a corner case and only occurs during specific actions taken by an administrator of a device under certain specifics actions which triggers the event. The event occurs less frequently on devices which are not configured with Virtual Chassis configurations, and more frequently on devices configured in Virtual Chassis configurations. This issue is not specific to any particular Junos OS platform. An Indicator of Compromise (IoC) may be seen by reviewing log files for the following error message seen by executing the following show statement: show log messages | grep storm Result to look for: /kernel: GENCFG: op 58 (Storm Control Blob) failed; err 1 (Unknown) This issue affects: Juniper Networks Junos OS: 14.1X53 versions before 14.1X53-D49 on EX Series; 15.1 versions before 15.1R7-S6; 15.1X49 versions before 15.1X49-D191, 15.1X49-D200 on SRX Series; 16.1 versions before 16.1R7-S7; 16.2 versions before 16.2R2-S11, 16.2R3; 17.1 versions before 17.1R2-S11, 17.1R3; 17.2 versions before 17.2R2-S8, 17.2R3-S3; 17.3 versions before 17.3R2-S5, 17.3R3-S7; 17.4 versions before 17.4R2-S9, 17.4R3; 18.1 versions before 18.1R3-S5; 18.2 versions before 18.2R2-S6, 18.2R3; 18.3 versions before 18.3R1-S7, 18.3R2-S3, 18.3R3; 18.4 versions before 18.4R1-S5, 18.4R2; 19.1 versions before 19.1R1-S4, 19.1R2.

Vulnerability Trend

References