CVE-2021-0293

Summary

A vulnerability in Juniper Networks Junos OS caused by Missing Release of Memory after Effective Lifetime leads to a memory leak each time the CLI command 'show system connections extensive' is executed. The amount of memory leaked on each execution depends on the number of TCP connections from and to the system. Repeated execution will cause more memory to leak and eventually daemons that need to allocate additionally memory and ultimately the kernel to crash, which will result in traffic loss. Continued execution of this command will cause a sustained Denial of Service (DoS) condition. An administrator can use the following CLI command to monitor for increase in memory consumption of the netstat process, if it exists: user@junos> show system processes extensive | match "username|netstat" PID USERNAME PRI NICE SIZE RES STATE C TIME WCPU COMMAND 21181 root 100 0 5458M 4913M CPU3 2 0:59 97.27% netstat The following log message might be observed if this issue happens: kernel: %KERN-3: pid 21181 (netstat), uid 0, was killed: out of swap space This issue affects Juniper Networks Junos OS 18.2 versions prior to 18.2R2-S8, 18.2R3-S7. 18.3 versions prior to 18.3R3-S4; 18.4 versions prior to 18.4R1-S8, 18.4R2-S6, 18.4R3-S7; 19.1 versions prior to 19.1R1-S6, 19.1R2-S2, 19.1R3-S4; 19.2 versions prior to 19.2R1-S6, 19.2R3-S2; 19.3 versions prior to 19.3R2-S6, 19.3R3-S1; 19.4 versions prior to 19.4R1-S4, 19.4R2-S3, 19.4R3-S1; 20.1 versions prior to 20.1R2; 20.2 versions prior to 20.2R2-S1, 20.2R3; 20.3 versions prior to 20.3R1-S1, 20.3R2; This issue does not affect Juniper Networks Junos OS versions prior to 18.2R1.

Affected Software

VendorProductVersion RangeStatus
Juniper NetworksJunos OSunspecified < 18.2R1unaffected
Juniper NetworksJunos OS18.3 < 18.3R3-S4affected
Juniper NetworksJunos OS18.4 < 18.4R1-S8, 18.4R2-S6, 18.4R3-S7affected
Juniper NetworksJunos OS19.1 < 19.1R1-S6, 19.1R2-S2, 19.1R3-S4affected
Juniper NetworksJunos OS19.2 < 19.2R1-S6, 19.2R3-S2affected
Juniper NetworksJunos OS19.3 < 19.3R2-S6, 19.3R3-S1affected
Juniper NetworksJunos OS19.4 < 19.4R1-S4, 19.4R2-S3, 19.4R3-S1affected
Juniper NetworksJunos OS20.1 < 20.1R2affected
Juniper NetworksJunos OS20.2 < 20.2R2-S1, 20.2R3affected
Juniper NetworksJunos OS20.3 < 20.3R1-S1, 20.3R2affected
Juniper NetworksJunos OS18.2 < 18.2R2-S8, 18.2R3-S7affected

Weaknesses

  • CWE-401: CWE-401 Missing Release of Memory after Effective Lifetime

Workarounds

Please use 'show system connections' (without extensive) and restrict access to 'show system connections extensive'.

To recover please use:

request system process terminate <PID>

with the PID for the netstat process from the output of 'show system processes extensive'.

ADP Enrichment

CVE Program Container

Additional References

References