No exploitation reported

CVE-2020-1649

No exploitation reported by the sources we read.

Published2020-07-17

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

When a device running Juniper Networks Junos OS with MPC7, MPC8, or MPC9 line cards installed and the system is configured for inline IP reassembly, used by L2TP, MAP-E, GRE, and IPIP, the packet forwarding engine (PFE) will become disabled upon receipt of small fragments requiring reassembly, generating the following error messages: [LOG: Err] MQSS(2): WO: Packet Error - Error Packets 1, Connection 29 [LOG: Err] eachip_hmcif_rx_intr_handler(7259): EA[2:0]: HMCIF Rx: Injected checksum error detected on WO response - Chunk Address 0x0 [LOG: Err] MQSS(2): DRD: RORD1: CMD reorder ID error - Command 11, Reorder ID 1960, QID 0 [LOG: Err] MQSS(2): DRD: UNROLL0: HMC chunk address error in stage 5 - Chunk Address: 0xc38fb1 [LOG: Notice] Error: /fpc/0/pfe/0/cm/0/MQSS(2)/2/MQSS_CMERROR_DRD_RORD_ENG_INT_REG_CMD_FSM_STATE_ERR (0x2203cc), scope: pfe, category: functional, severity: major, module: MQSS(2), type: DRD_RORD_ENG_INT: CMD FSM State Error [LOG: Notice] Performing action cmalarm for error /fpc/0/pfe/0/cm/0/MQSS(2)/2/MQSS_CMERROR_DRD_RORD_ENG_INT_REG_CMD_FSM_STATE_ERR (0x2203cc) in module: MQSS(2) with scope: pfe category: functional level: major [LOG: Notice] Performing action get-state for error /fpc/0/pfe/0/cm/0/MQSS(2)/2/MQSS_CMERROR_DRD_RORD_ENG_INT_REG_CMD_FSM_STATE_ERR (0x2203cc) in module: MQSS(2) with scope: pfe category: functional level: major [LOG: Notice] Performing action disable-pfe for error /fpc/0/pfe/0/cm/0/MQSS(2)/2/MQSS_CMERROR_DRD_RORD_ENG_INT_REG_CMD_FSM_STATE_ERR (0x2203cc) in module: MQSS(2) with scope: pfe category: functional level: major By continuously sending fragmented packets that cannot be reassembled, an attacker can repeatedly disable the PFE causing a sustained Denial of Service (DoS). This issue affects Juniper Networks Junos OS: 17.2 versions prior to 17.2R3-S4 on MX Series; 17.3 versions prior to 17.3R3-S8 on MX Series; 17.4 versions prior to 17.4R2-S9, 17.4R3-S1 on MX Series; 18.1 versions prior to 18.1R3-S10 on MX Series; 18.2 versions prior to 18.2R2-S6, 18.2R3-S3 on MX Series; 18.2X75 versions prior to 18.2X75-D34, 18.2X75-D41, 18.2X75-D53, 18.2X75-D65, 18.2X75-D430 on MX Series; 18.3 versions prior to 18.3R1-S7, 18.3R2-S4, 18.3R3-S2 on MX Series; 18.4 versions prior to 18.4R1-S6, 18.4R2-S4, 18.4R3 on MX Series; 19.1 versions prior to 19.1R1-S4, 19.1R2-S1, 19.1R3 on MX Series; 19.2 versions prior to 19.2R1-S3, 19.2R2 on MX Series; 19.3 versions prior to 19.3R2-S2, 19.3R3 on MX Series. This issue is specific to inline IP reassembly, introduced in Junos OS 17.2. Versions of Junos OS prior to 17.2 are unaffected by this vulnerability.

Timeline

dates in UTC

2020-07-1719:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2020-1649?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2020-1649?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Juniper junosversion to verify

Branch	Affected	Fixed in	Source
17.2	= 17.2	no fix published	NVD
17.3	= 17.3	no fix published	NVD
17.4	= 17.4	no fix published	NVD
18.1	= 18.1	no fix published	NVD
18.2	= 18.2	no fix published	NVD
18.2	= 18.2x75	no fix published	NVD
18.3	= 18.3	no fix published	NVD
18.4	= 18.4	no fix published	NVD
19.1	= 19.1	no fix published	NVD
19.2	= 19.2	no fix published	NVD
19.3	= 19.3	no fix published	NVD

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Advisories and patches

kb.juniper.netVendor Advisory
www.juniper.netVendor Advisory

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

CNACVSS 3.17.5read 2026-10-23
NVDCVSS 3.17.5read 2026-10-23
NVDCVSS 2.05read 2026-10-23
FIRST EPSSEPSS score1.1 %2026-10-22

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published: 2020-07-17
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2020-1649?

Is CVE-2020-1649 actively exploited?

Active exploitation of CVE-2020-1649 has not been confirmed. Its EPSS score was 1.1% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2020-1649?

CVE-2020-1649 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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