CVE-2020-1655
Junos OS: MX Series: PFE crash on MPC7/8/9 upon receipt of large packets requiring fragmentation
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 large packets requiring fragmentation, generating the following error messages: [LOG: Err] MQSS(0): WO: Packet Error - Error Packets 1, Connection 29 [LOG: Err] eachip_hmcif_rx_intr_handler(7259): EA[0:0]: HMCIF Rx: Injected checksum error detected on WO response - Chunk Address 0x0 [LOG: Err] MQSS(0): DRD: RORD1: CMD reorder ID error - Command 11, Reorder ID 1838, QID 0 [LOG: Err] MQSS(0): DRD: UNROLL0: HMC chunk length error in stage 5 - Chunk Address: 0x4321f3 [LOG: Err] MQSS(0): DRD: UNROLL0: HMC chunk address error in stage 5 - Chunk Address: 0x0 [LOG: Notice] Error: /fpc/8/pfe/0/cm/0/MQSS(0)/0/MQSS_CMERROR_DRD_RORD_ENG_INT_REG_CMD_FSM_STATE_ERR (0x2203cc), scope: pfe, category: functional, severity: major, module: MQSS(0), type: DRD_RORD_ENG_INT: CMD FSM State Error [LOG: Notice] Performing action cmalarm for error /fpc/8/pfe/0/cm/0/MQSS(0)/0/MQSS_CMERROR_DRD_RORD_ENG_INT_REG_CMD_FSM_STATE_ERR (0x2203cc) in module: MQSS(0) with scope: pfe category: functional level: major [LOG: Notice] Performing action get-state for error /fpc/8/pfe/0/cm/0/MQSS(0)/0/MQSS_CMERROR_DRD_RORD_ENG_INT_REG_CMD_FSM_STATE_ERR (0x2203cc) in module: MQSS(0) with scope: pfe category: functional level: major [LOG: Notice] Performing action disable-pfe for error /fpc/8/pfe/0/cm/0/MQSS(0)/0/MQSS_CMERROR_DRD_RORD_ENG_INT_REG_CMD_FSM_STATE_ERR (0x2203cc) in module: MQSS(0) 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-S10, 17.4R3-S2 on MX Series; 18.1 versions prior to 18.1R3-S10 on MX Series; 18.2 versions prior to 18.2R3-S3 on MX Series; 18.2X75 versions prior to 18.2X75-D41, 18.2X75-D430, 18.2X75-D65 on MX Series; 18.3 versions prior to 18.3R1-S7, 18.3R2-S4, 18.3R3-S1 on MX Series; 18.4 versions prior to 18.4R1-S7, 18.4R2-S4, 18.4R3 on MX Series; 19.1 versions prior to 19.1R1-S5, 19.1R2-S1, 19.1R3 on MX Series; 19.2 versions prior to 19.2R1-S4, 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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
5.3
Junos OS: MX Series: PFE crash on MPC7/8/9 upon receipt of large packets requiring fragmentation
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 large packets requiring fragmentation, generating the following error messages: [LOG: Err] MQSS(0): WO: Packet Error - Error Packets 1, Connection 29 [LOG: Err] eachip_hmcif_rx_intr_handler(7259): EA[0:0]: HMCIF Rx: Injected checksum error detected on WO response - Chunk Address 0x0 [LOG: Err] MQSS(0): DRD: RORD1: CMD reorder ID error - Command 11, Reorder ID 1838, QID 0 [LOG: Err] MQSS(0): DRD: UNROLL0: HMC chunk length error in stage 5 - Chunk Address: 0x4321f3 [LOG: Err] MQSS(0): DRD: UNROLL0: HMC chunk address error in stage 5 - Chunk Address: 0x0 [LOG: Notice] Error: /fpc/8/pfe/0/cm/0/MQSS(0)/0/MQSS_CMERROR_DRD_RORD_ENG_INT_REG_CMD_FSM_STATE_ERR (0x2203cc), scope: pfe, category: functional, severity: major, module: MQSS(0), type: DRD_RORD_ENG_INT: CMD FSM State Error [LOG: Notice] Performing action cmalarm for error /fpc/8/pfe/0/cm/0/MQSS(0)/0/MQSS_CMERROR_DRD_RORD_ENG_INT_REG_CMD_FSM_STATE_ERR (0x2203cc) in module: MQSS(0) with scope: pfe category: functional level: major [LOG: Notice] Performing action get-state for error /fpc/8/pfe/0/cm/0/MQSS(0)/0/MQSS_CMERROR_DRD_RORD_ENG_INT_REG_CMD_FSM_STATE_ERR (0x2203cc) in module: MQSS(0) with scope: pfe category: functional level: major [LOG: Notice] Performing action disable-pfe for error /fpc/8/pfe/0/cm/0/MQSS(0)/0/MQSS_CMERROR_DRD_RORD_ENG_INT_REG_CMD_FSM_STATE_ERR (0x2203cc) in module: MQSS(0) 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-S10, 17.4R3-S2 on MX Series; 18.1 versions prior to 18.1R3-S10 on MX Series; 18.2 versions prior to 18.2R3-S3 on MX Series; 18.2X75 versions prior to 18.2X75-D41, 18.2X75-D430, 18.2X75-D65 on MX Series; 18.3 versions prior to 18.3R1-S7, 18.3R2-S4, 18.3R3-S1 on MX Series; 18.4 versions prior to 18.4R1-S7, 18.4R2-S4, 18.4R3 on MX Series; 19.1 versions prior to 19.1R1-S5, 19.1R2-S1, 19.1R3 on MX Series; 19.2 versions prior to 19.2R1-S4, 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.
- Record
CVE-2020-1655- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Updated
- 2026-11-02
EUVDEUVD-2020-12520
5.3
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 large packets requiring fragmentation, generating the following error messages: [LOG: Err] MQSS(0): WO: Packet Error - Error Packets 1, Connection 29 [LOG: Err] eachip_hmcif_rx_intr_handler(7259): EA[0:0]: HMCIF Rx: Injected checksum error detected on WO response - Chunk Address 0x0 [LOG: Err] MQSS(0): DRD: RORD1: CMD reorder ID error - Command 11, Reorder ID 1838, QID 0 [LOG: Err] MQSS(0): DRD: UNROLL0: HMC chunk length error in stage 5 - Chunk Address: 0x4321f3 [LOG: Err] MQSS(0): DRD: UNROLL0: HMC chunk address error in stage 5 - Chunk Address: 0x0 [LOG: Notice] Error: /fpc/8/pfe/0/cm/0/MQSS(0)/0/MQSS_CMERROR_DRD_RORD_ENG_INT_REG_CMD_FSM_STATE_ERR (0x2203cc), scope: pfe, category: functional, severity: major, module: MQSS(0), type: DRD_RORD_ENG_INT: CMD FSM State Error [LOG: Notice] Performing action cmalarm for error /fpc/8/pfe/0/cm/0/MQSS(0)/0/MQSS_CMERROR_DRD_RORD_ENG_INT_REG_CMD_FSM_STATE_ERR (0x2203cc) in module: MQSS(0) with scope: pfe category: functional level: major [LOG: Notice] Performing action get-state for error /fpc/8/pfe/0/cm/0/MQSS(0)/0/MQSS_CMERROR_DRD_RORD_ENG_INT_REG_CMD_FSM_STATE_ERR (0x2203cc) in module: MQSS(0) with scope: pfe category: functional level: major [LOG: Notice] Performing action disable-pfe for error /fpc/8/pfe/0/cm/0/MQSS(0)/0/MQSS_CMERROR_DRD_RORD_ENG_INT_REG_CMD_FSM_STATE_ERR (0x2203cc) in module: MQSS(0) 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-S10, 17.4R3-S2 on MX Series; 18.1 versions prior to 18.1R3-S10 on MX Series; 18.2 versions prior to 18.2R3-S3 on MX Series; 18.2X75 versions prior to 18.2X75-D41, 18.2X75-D430, 18.2X75-D65 on MX Series; 18.3 versions prior to 18.3R1-S7, 18.3R2-S4, 18.3R3-S1 on MX Series; 18.4 versions prior to 18.4R1-S7, 18.4R2-S4, 18.4R3 on MX Series; 19.1 versions prior to 19.1R1-S5, 19.1R2-S1, 19.1R3 on MX Series; 19.2 versions prior to 19.2R1-S4, 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.
- Record
EUVD-2020-12520- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-g464-q8qp-3vg4 No score
When a device running Juniper Networks Junos OS with MPC7, MPC8, or MPC9 line cards installed and...
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 large packets requiring fragmentation, generating the following error messages: [LOG: Err] MQSS(0): WO: Packet Error - Error Packets 1, Connection 29 [LOG: Err] eachip_hmcif_rx_intr_handler(7259): EA[0:0]: HMCIF Rx: Injected checksum error detected on WO response - Chunk Address 0x0 [LOG: Err] MQSS(0): DRD: RORD1: CMD reorder ID error - Command 11, Reorder ID 1838, QID 0 [LOG: Err] MQSS(0): DRD: UNROLL0: HMC chunk length error in stage 5 - Chunk Address: 0x4321f3 [LOG: Err] MQSS(0): DRD: UNROLL0: HMC chunk address error in stage 5 - Chunk Address: 0x0 [LOG: Notice] Error: /fpc/8/pfe/0/cm/0/MQSS(0)/0/MQSS_CMERROR_DRD_RORD_ENG_INT_REG_CMD_FSM_STATE_ERR (0x2203cc), scope: pfe, category: functional, severity: major, module: MQSS(0), type: DRD_RORD_ENG_INT: CMD FSM State Error [LOG: Notice] Performing action cmalarm for error /fpc/8/pfe/0/cm/0/MQSS(0)/0/MQSS_CMERROR_DRD_RORD_ENG_INT_REG_CMD_FSM_STATE_ERR (0x2203cc) in module: MQSS(0) with scope: pfe category: functional level: major [LOG: Notice] Performing action get-state for error /fpc/8/pfe/0/cm/0/MQSS(0)/0/MQSS_CMERROR_DRD_RORD_ENG_INT_REG_CMD_FSM_STATE_ERR (0x2203cc) in module: MQSS(0) with scope: pfe category: functional level: major [LOG: Notice] Performing action disable-pfe for error /fpc/8/pfe/0/cm/0/MQSS(0)/0/MQSS_CMERROR_DRD_RORD_ENG_INT_REG_CMD_FSM_STATE_ERR (0x2203cc) in module: MQSS(0) 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-S10, 17.4R3-S2 on MX Series; 18.1 versions prior to 18.1R3-S10 on MX Series; 18.2 versions prior to 18.2R3-S3 on MX Series; 18.2X75 versions prior to 18.2X75-D41, 18.2X75-D430, 18.2X75-D65 on MX Series; 18.3 versions prior to 18.3R1-S7, 18.3R2-S4, 18.3R3-S1 on MX Series; 18.4 versions prior to 18.4R1-S7, 18.4R2-S4, 18.4R3 on MX Series; 19.1 versions prior to 19.1R1-S5, 19.1R2-S1, 19.1R3 on MX Series; 19.2 versions prior to 19.2R1-S4, 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.
- Record
GHSA-g464-q8qp-3vg4- Weakness
- CWE-400
- Updated
- 2026-11-02
NVD
5.3
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 large packets requiring fragmentation, generating the following error messages: [LOG: Err] MQSS(0): WO: Packet Error - Error Packets 1, Connection 29 [LOG: Err] eachip_hmcif_rx_intr_handler(7259): EA[0:0]: HMCIF Rx: Injected checksum error detected on WO response - Chunk Address 0x0 [LOG: Err] MQSS(0): DRD: RORD1: CMD reorder ID error - Command 11, Reorder ID 1838, QID 0 [LOG: Err] MQSS(0): DRD: UNROLL0: HMC chunk length error in stage 5 - Chunk Address: 0x4321f3 [LOG: Err] MQSS(0): DRD: UNROLL0: HMC chunk address error in stage 5 - Chunk Address: 0x0 [LOG: Notice] Error: /fpc/8/pfe/0/cm/0/MQSS(0)/0/MQSS_CMERROR_DRD_RORD_ENG_INT_REG_CMD_FSM_STATE_ERR (0x2203cc), scope: pfe, category: functional, severity: major, module: MQSS(0), type: DRD_RORD_ENG_INT: CMD FSM State Error [LOG: Notice] Performing action cmalarm for error /fpc/8/pfe/0/cm/0/MQSS(0)/0/MQSS_CMERROR_DRD_RORD_ENG_INT_REG_CMD_FSM_STATE_ERR (0x2203cc) in module: MQSS(0) with scope: pfe category: functional level: major [LOG: Notice] Performing action get-state for error /fpc/8/pfe/0/cm/0/MQSS(0)/0/MQSS_CMERROR_DRD_RORD_ENG_INT_REG_CMD_FSM_STATE_ERR (0x2203cc) in module: MQSS(0) with scope: pfe category: functional level: major [LOG: Notice] Performing action disable-pfe for error /fpc/8/pfe/0/cm/0/MQSS(0)/0/MQSS_CMERROR_DRD_RORD_ENG_INT_REG_CMD_FSM_STATE_ERR (0x2203cc) in module: MQSS(0) 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-S10, 17.4R3-S2 on MX Series; 18.1 versions prior to 18.1R3-S10 on MX Series; 18.2 versions prior to 18.2R3-S3 on MX Series; 18.2X75 versions prior to 18.2X75-D41, 18.2X75-D430, 18.2X75-D65 on MX Series; 18.3 versions prior to 18.3R1-S7, 18.3R2-S4, 18.3R3-S1 on MX Series; 18.4 versions prior to 18.4R1-S7, 18.4R2-S4, 18.4R3 on MX Series; 19.1 versions prior to 19.1R1-S5, 19.1R2-S1, 19.1R3 on MX Series; 19.2 versions prior to 19.2R1-S4, 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.
- Record
CVE-2020-1655- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:N/I:N/A:P - Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2020-1655 is a medium vulnerability (CVSS 5.3) in Juniper Junos, published July 17, 2020. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.04%, the 64th percentile. No source names a fixed version.