Denial of serivce when processing DHCP traffic in Juniper Junos OS

Published: 2021-01-14
Risk Medium
Patch available YES
Number of vulnerabilities 1
CVE ID CVE-2021-0217
Exploitation vector Local network
Public exploit N/A
Vulnerable software
Juniper Junos OS
Operating systems & Components / Operating system


Security Advisory

This security advisory describes one medium risk vulnerability.

1) Resource exhaustion

Risk: Medium

CVSSv3: 6.4 [CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H/E:U/RL:O/RC:C] [PCI]

CVE-ID: CVE-2021-0217

CWE-ID: CWE-400 - Uncontrolled Resource Consumption ('Resource Exhaustion')

Exploit availability: No


The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to insufficient validation of user-supplied input when processing DHCP packets from adjacent clients on EX Series and QFX Series switches. An attacker on the local network can send specially crafted HDCP packets to the affected system and exhaust DMA memory or crash the fxpc process.


Install updates from vendor's website.

This issue affects Juniper Networks Junos OS on EX Series and QFX Series:

  • 17.4R3 versions prior to 17.4R3-S3;
  • 18.1R3 versions between 18.1R3-S6 and 18.1R3-S11;
  • 18.2R3 versions prior to 18.2R3-S6;
  • 18.3R3 versions prior to 18.3R3-S4;
  • 18.4R2 versions prior to 18.4R2-S5;
  • 18.4R3 versions prior to 18.4R3-S6;
  • 19.1 versions between 19.1R2 and 19.1R3-S3;
  • 19.2 versions prior to 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.

Junos OS versions prior to 17.4R3 are unaffected by this vulnerability.

Vulnerable software versions

Juniper Junos OS: before 17.4R3-S3, 18.1R3-S11, 18.2R3-S6, 18.3R3-S4, 18.4R2-S5, 18.4R2-S7, 18.4R3-S6, 19.1R1-S6, 19.1R3-S3, 19.2R3-S1, 19.3R2-S5, 19.3R3, 19.4R2-S2, 19.4R3, 20.1R2, 20.2R1-S2, 20.2R2, 20.3R1

CPE External links

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the local network (LAN).

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.