Vulnerability Description
An Incorrect Behavior Order vulnerability in the MAP-E automatic tunneling mechanism of Juniper Networks Junos OS allows an attacker to send certain malformed IPv4 or IPv6 packets to cause a Denial of Service (DoS) to the PFE on the device which is disabled as a result of the processing of these packets. Continued receipt and processing of these malformed IPv4 or IPv6 packets will create a sustained Denial of Service (DoS) condition. This issue only affects MPC 7/8/9/10/11 cards, when MAP-E IP reassembly is enabled on these cards. An indicator of compromise is the output: FPC ["FPC ID" # e.g. "0"] PFE #{PFE ID # e.g. "1"] : Fabric Disabled Example: FPC 0 PFE #1 : Fabric Disabled when using the command: show chassis fabric fpcs An example of a healthy result of the command use would be: user@device-re1> show chassis fabric fpcs Fabric management FPC state: FPC 0 PFE #0 Plane 0: Plane enabled Plane 1: Plane enabled Plane 2: Plane enabled Plane 3: Plane enabled Plane 4: Plane enabled Plane 5: Plane enabled Plane 6: Plane enabled Plane 7: Plane enabled This issue affects: Juniper Networks Junos OS on MX Series with MPC 7/8/9/10/11 cards, when MAP-E IP reassembly is enabled on these cards. 17.2 version 17.2R1 and later versions; 17.3 versions prior to 17.3R3-S9; 17.4 versions prior to 17.4R2-S12, 17.4R3-S3; 18.1 versions prior to 18.1R3-S11; 18.2 versions prior to 18.2R2-S6, 18.2R3-S3; 18.3 versions prior to 18.3R2-S4, 18.3R3-S1; 18.4 versions prior to 18.4R1-S8, 18.4R2-S5, 18.4R3; 19.1 versions prior to 19.1R1-S6, 19.1R2-S2, 19.1R3; 19.2 versions prior to 19.2R1-S5, 19.2R2; 19.3 versions prior to 19.3R2-S5, 19.3R3. This issue does not affect Juniper Networks Junos OS versions prior to 17.2R1.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Juniper | Junos | 17.2 |
| Juniper | Mx10 | - |
| Juniper | Mx10000 | - |
| Juniper | Mx10003 | - |
| Juniper | Mx10008 | - |
| Juniper | Mx10016 | - |
| Juniper | Mx104 | - |
| Juniper | Mx150 | - |
| Juniper | Mx2008 | - |
| Juniper | Mx2010 | - |
| Juniper | Mx2020 | - |
| Juniper | Mx204 | - |
| Juniper | Mx240 | - |
| Juniper | Mx40 | - |
| Juniper | Mx480 | - |
| Juniper | Mx5 | - |
| Juniper | Mx80 | - |
| Juniper | Mx960 | - |
Related Weaknesses (CWE)
References
- https://kb.juniper.net/JSA11247ExploitMitigationVendor Advisory
- https://www.juniper.net/documentation/en_US/junos/topics/topic-map/map-e-configuVendor Advisory
- https://kb.juniper.net/JSA11247ExploitMitigationVendor Advisory
- https://www.juniper.net/documentation/en_US/junos/topics/topic-map/map-e-configuVendor Advisory
FAQ
What is CVE-2021-31379?
CVE-2021-31379 is a vulnerability with a CVSS score of 7.5 (HIGH). An Incorrect Behavior Order vulnerability in the MAP-E automatic tunneling mechanism of Juniper Networks Junos OS allows an attacker to send certain malformed IPv4 or IPv6 packets to cause a Denial of...
How severe is CVE-2021-31379?
CVE-2021-31379 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2021-31379?
Check the references section above for vendor advisories and patch information. Affected products include: Juniper Junos, Juniper Mx10, Juniper Mx10000, Juniper Mx10003, Juniper Mx10008.