CVE-2020-1655

Junos OS: MX Series: PFE crash on MPC7/8/9 upon receipt of large packets requiring fragmentation

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.

Remediation

Solution:

The following software releases have been updated to resolve this specific issue: Junos OS 17.2R3-S4, 17.3R3-S8, 17.4R2-S10, 17.4R3-S2, 18.1R3-S10, 18.2R3-S3, 18.2X75-D41, 18.2X75-D430, 18.2X75-D65, 18.3R1-S7, 18.3R2-S4, 18.3R3-S1, 18.4R1-S7, 18.4R2-S4, 18.4R3, 19.1R1-S5, 19.1R2-S1, 19.1R3, 19.2R1-S4, 19.2R2, 19.3R2-S2, 19.3R3, 19.4R1, 19.4R2, 20.1R1, and all subsequent releases.

Workaround:

There are no available workarounds for this issue.

5.3

CVSS

Severity: Medium

CVSS 3.1 •

CVSS 2.0 •

EPSS 0.33%

Vendor Advisory juniper.net Vendor Advisory juniper.net

Affected: Juniper Networks Junos OS

References

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

Frequently Asked Questions

What is the severity of CVE-2020-1655?: CVE-2020-1655 has been scored as a medium severity vulnerability.
How to fix CVE-2020-1655?: To fix CVE-2020-1655: The following software releases have been updated to resolve this specific issue: Junos OS 17.2R3-S4, 17.3R3-S8, 17.4R2-S10, 17.4R3-S2, 18.1R3-S10, 18.2R3-S3, 18.2X75-D41, 18.2X75-D430, 18.2X75-D65, 18.3R1-S7, 18.3R2-S4, 18.3R3-S1, 18.4R1-S7, 18.4R2-S4, 18.4R3, 19.1R1-S5, 19.1R2-S1, 19.1R3, 19.2R1-S4, 19.2R2, 19.3R2-S2, 19.3R3, 19.4R1, 19.4R2, 20.1R1, and all subsequent releases.
Is CVE-2020-1655 being actively exploited in the wild?: As for now, there are no information to confirm that CVE-2020-1655 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2020-1655?: CVE-2020-1655 affects Juniper Networks Junos OS.