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 versions prior to 16.1R7-S7; 16.2 versions prior to 16.2R2-S11; 17.1 versions prior to 17.1R2-S11, 17.1R3-S2; 17.2 versions prior to 17.2R3-S3; 17.2X75 versions prior to 17.2X75-D44; 17.3 versions prior to 17.3R3-S7; 17.4 versions prior to 17.4R2-S9, 17.4R3; 18.1 versions prior to 18.1R3-S9; 18.2 versions prior to 18.2R2-S6, 18.2R3-S2; 18.2X75 versions prior to 18.2X75-D12, 18.2X75-D33, 18.2X75-D435, 18.2X75-D60; 18.3 versions prior to 18.3R1-S7, 18.3R2-S3, 18.3R3-S1; 18.4 versions prior to 18.4R1-S5, 18.4R2-S3, 18.4R3; 19.1 versions prior to 19.1R1-S4, 19.1R2; 19.2 versions prior to 19.2R1-S3, 19.2R2; 19.3 versions prior to 19.3R2.
CVE-2020-1656
This high-severity CVE scores 8.8 under NVD CVSS v3. EPSS exploit probability: 1.1%, top 38% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
- High severity, but no confirmed exploitation yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 8.8
- EG Score
- 8.8(medium)
- EG Risk
- 45(Track)EG Risk 45/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity88% × 45%Exploitation1% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS
- 62.4%
- KEV
- Not listed
Published
October 16, 2020
Last Modified
November 21, 2024
References (8)
- sirt@juniperhttps://kb.juniper.net/JSA11049
- sirt@juniperhttps://www.juniper.net/documentation/en_US/junos/topics/reference/command-summary/show-dhcpv6-relay-statistics.html
- sirt@juniperhttps://www.juniper.net/documentation/en_US/junos/topics/topic-map/dhcp-relay-agent-security-devices.html
- sirt@juniperhttps://www.juniper.net/documentation/en_US/junos/topics/topic-map/dhcpv6-relay-agent-overview.html
- af854a3a-2127-422b-91ae-364da2661108https://kb.juniper.net/JSA11049
- af854a3a-2127-422b-91ae-364da2661108https://www.juniper.net/documentation/en_US/junos/topics/reference/command-summary/show-dhcpv6-relay-statistics.html
- af854a3a-2127-422b-91ae-364da2661108https://www.juniper.net/documentation/en_US/junos/topics/topic-map/dhcp-relay-agent-security-devices.html
- af854a3a-2127-422b-91ae-364da2661108https://www.juniper.net/documentation/en_US/junos/topics/topic-map/dhcpv6-relay-agent-overview.html
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 13× in last 7d / 44× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
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- 2026-05-23 06:37 UTCGHSA enrichment
Related CVEs(same CWE)
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Frequently asked(5)
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Dependency Blast Radius
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