CVE-2020-1661

Junos OS: jdhcpd process crash when forwarding a malformed DHCP packet.

Description

On Juniper Networks Junos OS devices configured as a DHCP forwarder, the Juniper Networks Dynamic Host Configuration Protocol Daemon (jdhcp) process might crash when receiving a malformed DHCP packet. This issue only affects devices configured as DHCP forwarder with forward-only option, that forward specified DHCP client packets, without creating a new subscriber session. The jdhcpd daemon automatically restarts without intervention, but continuous receipt of the malformed DHCP packet will repeatedly crash jdhcpd, leading to an extended Denial of Service (DoS) condition. This issue can be triggered only by DHCPv4, it cannot be triggered by DHCPv6. This issue affects Juniper Networks Junos OS: 12.3 versions prior to 12.3R12-S16; 12.3X48 versions prior to 12.3X48-D105 on SRX Series; 14.1X53 versions prior to 14.1X53-D60 on EX and QFX Series; 15.1 versions prior to 15.1R7-S7; 15.1X49 versions prior to 15.1X49-D221, 15.1X49-D230 on SRX Series; 15.1X53 versions prior to 15.1X53-D593 on EX2300/EX3400; 16.1 versions prior to 16.1R7-S5.

Remediation

Solution:

The following software releases have been updated to resolve this specific issue: Junos OS 12.3R12-S16, 12.3X48-D105, 15.1R7-S7, 15.1X49-D221, 15.1X49-D230, 15.1X53-D593, 16.1R7-S5, 16.2R1 and all subsequent releases.

Workaround:

There are no viable workarounds for this issue.

5.3

CVSS

Severity: Medium

CVSS 3.1 •

CVSS 2.0 •

EPSS 0.27%

Vendor Advisory juniper.net

Affected: Juniper Networks Junos OS

References

Link	Tags
https://kb.juniper.net/JSA11056	vendor advisory

Frequently Asked Questions

What is the severity of CVE-2020-1661?: CVE-2020-1661 has been scored as a medium severity vulnerability.
How to fix CVE-2020-1661?: To fix CVE-2020-1661: The following software releases have been updated to resolve this specific issue: Junos OS 12.3R12-S16, 12.3X48-D105, 15.1R7-S7, 15.1X49-D221, 15.1X49-D230, 15.1X53-D593, 16.1R7-S5, 16.2R1 and all subsequent releases.
Is CVE-2020-1661 being actively exploited in the wild?: As for now, there are no information to confirm that CVE-2020-1661 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2020-1661?: CVE-2020-1661 affects Juniper Networks Junos OS, Juniper Networks Junos OS, Juniper Networks Junos OS, Juniper Networks Junos OS.