CVE intelligence and bounded remediation

CVE-2020-1656 — Juniper Junos security vulnerability

High CVSS 8.8

The DHCPv6 Relay-Agent service, part of the Juniper Enhanced jdhcpd daemon shipped with Juniper Networks Junos OS has an Improper Input Validation vulnerability which will result in a Denial of Service (DoS) condition when a DHCPv6 client sends a specific DHPCv6 message allowing an attacker to potentially perform a Remote Code Execution (RCE) attack on the target device. Continuous receipt of the specific DHCPv6 client message will result in an extended Denial of Service (DoS) condition. If adjacent devices are also configured to relay DHCP packets, and are not affected by this issue and simply transparently forward unprocessed client DHCPv6 messages, then the attack vector can be a Network-based attack, instead of an Adjacent-device attack. No other DHCP services are affected. Receipt of the packet without configuration of the DHCPv6 Relay-Agent service, will not result in exploitability of this issue. This issue affects Juniper Networks Junos OS: 12.3 versions prior to 12.3R12-S15; 12.3X48 versions prior to 12.3X48-D95; 14.1X53 versions prior to 14.1X53-D53; 15.1 versions prior to 15.1R7-S6; 15.1X49 versions prior to 15.1X49-D200; 15.1X53 versions prior to 15.1X53-D593; 16.1 ver…

Severity
High
CVSS
8.8 (3.1)
Published
2020-10-16
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-20, CWE-476

Affected products

  • juniper / junos / 12.3

Showing 1 representative product identities from 326 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Buffer bounds, memory safety, and memory corruption

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Identify affected native-code versions, build flags, architectures, parsers, codecs, drivers, and input paths in all shipped artifacts.
  • Determine whether untrusted data reaches the affected routine and the process privilege, sandbox, and network exposure.
  • Confirm statically linked, vendored, firmware, and platform-provided copies, not only package-manager records.

Remediate safely

  • Apply the maintained upstream correction or replace the affected component, then rebuild every dependent artifact from clean inputs.
  • Adopt bounds-checked interfaces, validated sizes and integer conversions, clear ownership, and memory-safe components where practical.
  • Enable supported compiler and runtime hardening and add sanitized tests and fuzz regression seeds derived from non-weaponized fixtures.

Authoritative sources

Complete CVE record and remediation plan

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