CVE-2020-1649

Junos OS: MX Series: PFE crash on MPC7/8/9 upon receipt of small fragments requiring reassembly

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.

Remediation

Solution:

The following software releases have been updated to resolve this specific issue: Junos OS 17.2R3-S4, 17.3R3-S8, 17.4R2-S9, 17.4R3-S1, 18.1R3-S10, 18.2R2-S6, 18.2R3-S3, 18.2X75-D34, 18.2X75-D41, 18.2X75-D53, 18.2X75-D65, 18.2X75-D430, 18.3R1-S7, 18.3R2-S4, 18.3R3-S2, 18.4R1-S6, 18.4R2-S4, 18.4R3, 19.1R1-S4, 19.1R2-S1, 19.1R3, 19.2R1-S3, 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.

7.5

CVSS

Severity: High

CVSS 3.1 •

CVSS 2.0 •

EPSS 0.41%

Vendor Advisory juniper.net Vendor Advisory juniper.net

Affected: Juniper Networks Junos OS

References

Link	Tags
https://kb.juniper.net/JSA11036	vendor advisory
https://www.juniper.net/documentation/en_US/junos/topics/topic-map/l2tp-lns-inline-service-interfaces.html	vendor advisory

Frequently Asked Questions

What is the severity of CVE-2020-1649?: CVE-2020-1649 has been scored as a high severity vulnerability.
How to fix CVE-2020-1649?: To fix CVE-2020-1649: The following software releases have been updated to resolve this specific issue: Junos OS 17.2R3-S4, 17.3R3-S8, 17.4R2-S9, 17.4R3-S1, 18.1R3-S10, 18.2R2-S6, 18.2R3-S3, 18.2X75-D34, 18.2X75-D41, 18.2X75-D53, 18.2X75-D65, 18.2X75-D430, 18.3R1-S7, 18.3R2-S4, 18.3R3-S2, 18.4R1-S6, 18.4R2-S4, 18.4R3, 19.1R1-S4, 19.1R2-S1, 19.1R3, 19.2R1-S3, 19.2R2, 19.3R2-S2, 19.3R3, 19.4R1, 19.4R2, 20.1R1, and all subsequent releases.
Is CVE-2020-1649 being actively exploited in the wild?: As for now, there are no information to confirm that CVE-2020-1649 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-2020-1649?: CVE-2020-1649 affects Juniper Networks Junos OS.