CVE-2020-1655 Information

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 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.

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Reference

https://kb.juniper.net/JSA11041 https://www.juniper.net/documentation/en_US/junos/topics/topic-map/l2tp-lns-inline-service-interfaces.html

Attack Complexity

LOW

Privileges Required

NONE

User Interaction Required

NONE

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

NONE

Availability Impact

NONE

Base Score

LOW

Base Severity

5.3