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CVE-2021-31379

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.

Security Impact Summary

This vulnerability carries a HIGH severity rating with a CVSS v3.1 score of 7.5, indicating it can be exploited remotely over the network with relatively low complexity without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts and availability (service disruption) for affected systems. Impacting 18 products from juniper, from juniper, from juniper and 15 others, organizations running these solutions should prioritize assessment and patching.

Historical Context

Reported in 2021, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.

Published

2021-10-19T19:15:11.077

Last Modified

2024-11-21T06:05:33.673

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 7.5 (HIGH)

CVSSv2 Vector

AV:N/AC:M/Au:N/C:N/I:N/A:P

Access Vector: NETWORK
Access Complexity: MEDIUM
Authentication: NONE
Confidentiality Impact: NONE
Integrity Impact: NONE
Availability Impact: PARTIAL

Exploitability Score

8.6

Impact Score

2.9

Weaknesses

Type: Secondary
CWE-696
Type: Primary
NVD-CWE-Other

Affected Vendors & Products

Type	Vendor	Product	Version/Range	Vulnerable?
Operating System	juniper	junos	17.2	Yes
Operating System	juniper	junos	17.2	Yes
Operating System	juniper	junos	17.2	Yes
Operating System	juniper	junos	17.2	Yes
Operating System	juniper	junos	17.2	Yes
Operating System	juniper	junos	17.2	Yes
Operating System	juniper	junos	17.2	Yes
Operating System	juniper	junos	17.2	Yes
Operating System	juniper	junos	17.2	Yes
Operating System	juniper	junos	17.2	Yes
Operating System	juniper	junos	17.2	Yes
Operating System	juniper	junos	17.2	Yes
Operating System	juniper	junos	17.2	Yes
Operating System	juniper	junos	17.2	Yes
Operating System	juniper	junos	17.2	Yes
Operating System	juniper	junos	17.2	Yes
Operating System	juniper	junos	17.2	Yes
Operating System	juniper	junos	17.2	Yes
Operating System	juniper	junos	17.2	Yes
Operating System	juniper	junos	17.2x75	Yes
Operating System	juniper	junos	17.2x75	Yes
Operating System	juniper	junos	17.2x75	Yes
Operating System	juniper	junos	17.2x75	Yes
Operating System	juniper	junos	17.2x75	Yes
Operating System	juniper	junos	17.2x75	Yes
Operating System	juniper	junos	17.2x75	Yes
Operating System	juniper	junos	17.2x75	Yes
Operating System	juniper	junos	17.2x75	Yes
Operating System	juniper	junos	17.2x75	Yes
Operating System	juniper	junos	17.3	Yes
Operating System	juniper	junos	17.3	Yes
Operating System	juniper	junos	17.3	Yes
Operating System	juniper	junos	17.3	Yes
Operating System	juniper	junos	17.3	Yes
Operating System	juniper	junos	17.3	Yes
Operating System	juniper	junos	17.3	Yes
Operating System	juniper	junos	17.3	Yes
Operating System	juniper	junos	17.3	Yes
Operating System	juniper	junos	17.3	Yes
Operating System	juniper	junos	17.3	Yes
Operating System	juniper	junos	17.3	Yes
Operating System	juniper	junos	17.3	Yes
Operating System	juniper	junos	17.3	Yes
Operating System	juniper	junos	17.3	Yes
Operating System	juniper	junos	17.3	Yes
Operating System	juniper	junos	17.3	Yes
Operating System	juniper	junos	17.3	Yes
Operating System	juniper	junos	17.3	Yes
Operating System	juniper	junos	17.3	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	17.4	Yes
Operating System	juniper	junos	18.1	Yes
Operating System	juniper	junos	18.1	Yes
Operating System	juniper	junos	18.1	Yes
Operating System	juniper	junos	18.1	Yes
Operating System	juniper	junos	18.1	Yes
Operating System	juniper	junos	18.1	Yes
Operating System	juniper	junos	18.1	Yes
Operating System	juniper	junos	18.1	Yes
Operating System	juniper	junos	18.1	Yes
Operating System	juniper	junos	18.1	Yes
Operating System	juniper	junos	18.1	Yes
Operating System	juniper	junos	18.1	Yes
Operating System	juniper	junos	18.1	Yes
Operating System	juniper	junos	18.1	Yes
Operating System	juniper	junos	18.1	Yes
Operating System	juniper	junos	18.1	Yes
Operating System	juniper	junos	18.1	Yes
Operating System	juniper	junos	18.1	Yes
Operating System	juniper	junos	18.2	Yes
Operating System	juniper	junos	18.2	Yes
Operating System	juniper	junos	18.2	Yes
Operating System	juniper	junos	18.2	Yes
Operating System	juniper	junos	18.2	Yes
Operating System	juniper	junos	18.2	Yes
Operating System	juniper	junos	18.2	Yes
Operating System	juniper	junos	18.2	Yes
Operating System	juniper	junos	18.2	Yes
Operating System	juniper	junos	18.2	Yes
Operating System	juniper	junos	18.2	Yes
Operating System	juniper	junos	18.2	Yes
Operating System	juniper	junos	18.2	Yes
Operating System	juniper	junos	18.2	Yes
Operating System	juniper	junos	18.2	Yes
Operating System	juniper	junos	18.2	Yes
Operating System	juniper	junos	18.2	Yes
Operating System	juniper	junos	18.3	Yes
Operating System	juniper	junos	18.3	Yes
Operating System	juniper	junos	18.3	Yes
Operating System	juniper	junos	18.3	Yes
Operating System	juniper	junos	18.3	Yes
Operating System	juniper	junos	18.3	Yes
Operating System	juniper	junos	18.3	Yes
Operating System	juniper	junos	18.3	Yes
Operating System	juniper	junos	18.3	Yes
Operating System	juniper	junos	18.3	Yes
Operating System	juniper	junos	18.3	Yes
Operating System	juniper	junos	18.3	Yes
Operating System	juniper	junos	18.3	Yes
Operating System	juniper	junos	18.3	Yes
Operating System	juniper	junos	18.4	Yes
Operating System	juniper	junos	18.4	Yes
Operating System	juniper	junos	18.4	Yes
Operating System	juniper	junos	18.4	Yes
Operating System	juniper	junos	18.4	Yes
Operating System	juniper	junos	18.4	Yes
Operating System	juniper	junos	18.4	Yes
Operating System	juniper	junos	18.4	Yes
Operating System	juniper	junos	18.4	Yes
Operating System	juniper	junos	18.4	Yes
Operating System	juniper	junos	18.4	Yes
Operating System	juniper	junos	18.4	Yes
Operating System	juniper	junos	18.4	Yes
Operating System	juniper	junos	18.4	Yes
Operating System	juniper	junos	19.1	Yes
Operating System	juniper	junos	19.1	Yes
Operating System	juniper	junos	19.1	Yes
Operating System	juniper	junos	19.1	Yes
Operating System	juniper	junos	19.1	Yes
Operating System	juniper	junos	19.1	Yes
Operating System	juniper	junos	19.1	Yes
Operating System	juniper	junos	19.1	Yes
Operating System	juniper	junos	19.1	Yes
Operating System	juniper	junos	19.2	Yes
Operating System	juniper	junos	19.2	Yes
Operating System	juniper	junos	19.2	Yes
Operating System	juniper	junos	19.2	Yes
Operating System	juniper	junos	19.2	Yes
Operating System	juniper	junos	19.2	Yes
Operating System	juniper	junos	19.3	Yes
Operating System	juniper	junos	19.3	Yes
Operating System	juniper	junos	19.3	Yes
Operating System	juniper	junos	19.3	Yes
Operating System	juniper	junos	19.3	Yes
Operating System	juniper	junos	19.3	Yes
Operating System	juniper	junos	19.3	Yes
Operating System	juniper	junos	19.3	Yes
Hardware	juniper	mx10	-	No
Hardware	juniper	mx10000	-	No
Hardware	juniper	mx10003	-	No
Hardware	juniper	mx10008	-	No
Hardware	juniper	mx10016	-	No
Hardware	juniper	mx104	-	No
Hardware	juniper	mx150	-	No
Hardware	juniper	mx2008	-	No
Hardware	juniper	mx2010	-	No
Hardware	juniper	mx2020	-	No
Hardware	juniper	mx204	-	No
Hardware	juniper	mx240	-	No
Hardware	juniper	mx40	-	No
Hardware	juniper	mx480	-	No
Hardware	juniper	mx5	-	No
Hardware	juniper	mx80	-	No
Hardware	juniper	mx960	-	No

References

https://kb.juniper.net/JSA11247 Exploit, Mitigation, Vendor Advisory ([email protected])
https://www.juniper.net/documentation/en_US/junos/topics/topic-map/map-e-configuring.html Vendor Advisory ([email protected])
https://kb.juniper.net/JSA11247 Exploit, Mitigation, Vendor Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://www.juniper.net/documentation/en_US/junos/topics/topic-map/map-e-configuring.html Vendor Advisory (af854a3a-2127-422b-91ae-364da2661108)

How SecUtils Interprets This CVE

SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For juniper's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.