An Improper Validation of Syntactic Correctness of Input vulnerability in the Juniper DHCP daemon (jdhcpd) of Juniper Networks Junos OS allows an adjacent unauthenticated attacker sending a malformed DHCP packet to cause a crash of jdhcpd and thereby a Denial of Service (DoS).

If option-82 is configured in a DHCP snooping / -security scenario, jdhcpd crashes if a specific malformed DHCP request packet is received. The DHCP functionality is impacted while jdhcpd restarts, and continued exploitation of the vulnerability will lead to the unavailability of the DHCP service and thereby a sustained DoS.

This issue affects Juniper Networks Junos OS:

• 13.2 version 13.2R1 and later versions prior to 15.1R7-S11;
• 18.3 versions prior to 18.3R3-S6;
• 18.4 versions prior to 18.4R2-S9, 18.4R3-S10;
• 19.1 versions prior to 19.1R2-S3, 19.1R3-S7;
• 19.2 versions prior to 19.2R1-S8, 19.2R3-S4;
• 19.3 versions prior to 19.3R2-S7, 19.3R3-S4;
• 19.4 versions prior to 19.4R3-S6;
• 20.1 versions prior to 20.1R3-S3;
• 20.2 versions prior to 20.2R3-S3;
• 20.3 versions prior to 20.3R3-S1;
• 20.4 versions prior to 20.4R3;
• 21.1 versions prior to 21.1R2-S1, 21.1R3;
• 21.2 versions prior to 21.2R1-S1, 21.2R2.

This issue does not affect Juniper Networks Junos OS version 12.3R12 and prior versions.

For a device to be affected at least one of the following configuration statements needs to be present:

[ bridge-domains <bridge-domain-name> forwarding-options dhcp-security option-82 ... ]

or

[ vlans <vlan-name> forwarding-options dhcp-security option-82 ... ]

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-2022-22176 .

The following software releases have been updated to resolve this specific issue: 15.1R7-S11, 18.3R3-S6, 18.4R2-S9, 18.4R3-S10, 19.1R2-S3, 19.1R3-S7, 19.2R1-S8, 19.2R3-S4, 19.3R2-S7, 19.3R3-S4, 19.4R3-S6, 20.1R3-S3, 20.2R3-S3, 20.3R3-S1, 20.4R3, 21.1R2-S1, 21.1R3, 21.2R1-S1, 21.2R2, 21.3R1, and all subsequent releases.

This issue is being tracked as  1606794 .

There are no known workarounds for this issue.