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CVE-2021-31378

In broadband environments, including but not limited to Enhanced Subscriber Management, (CHAP, PPP, DHCP, etc.), on Juniper Networks Junos OS devices where RADIUS servers are configured for managing subscriber access and a subscriber is logged in and then requests to logout, the subscriber may be forced into a "Terminating" state by an attacker who is able to send spoofed messages appearing to originate from trusted RADIUS server(s) destined to the device in response to the subscriber's request. These spoofed messages cause the Junos OS General Authentication Service (authd) daemon to force the broadband subscriber into this "Terminating" state which the subscriber will not recover from thereby causing a Denial of Service (DoS) to the endpoint device. Once in the "Terminating" state, the endpoint subscriber will no longer be able to access the network. Restarting the authd daemon on the Junos OS device will temporarily clear the subscribers out of the "Terminating" state. As long as the attacker continues to send these spoofed packets and subscribers request to be logged out, the subscribers will be returned to the "Terminating" state thereby creating a persistent Denial of Service to the subscriber. An indicator of compromise may be seen by displaying the output of "show subscribers summary". The presence of subscribers in the "Terminating" state may indicate the issue is occurring. This issue affects: Juniper Networks Junos OS 17.3 versions prior to 17.3R3-S12; 17.4 versions prior to 17.4R3-S5; 18.1 versions prior to 18.1R3-S13; 18.2 versions prior to 18.2R3-S8; 18.3 versions prior to 18.3R3-S5; 18.4 versions prior to 18.4R2-S8, 18.4R3-S9; 19.1 versions prior to 19.1R3-S6; 19.2 versions prior to 19.2R1-S7, 19.2R3-S3; 19.3 versions prior to 19.3R2-S6, 19.3R3-S3; 19.4 versions prior to 19.4R1-S4, 19.4R1-S4, 19.4R3-S3; 20.1 versions prior to 20.1R3; 20.2 versions prior to 20.2R3-S1; 20.3 versions prior to 20.3R3; 20.4 versions prior to 20.4R3; 21.1 versions prior to 21.1R2. This issue does not affect: Juniper Networks Junos OS 12.3 version 12.3R1 and later versions; 15.1 version 15.1R1 and later versions.

Security Impact Summary

This vulnerability carries a MEDIUM severity rating with a CVSS v3.1 score of 6.8, indicating it can be exploited remotely over the network but requires specific conditions to be met without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts and availability (service disruption) for affected systems. Impacting 1 product from juniper 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

2021-10-19T19:15:11.023

Last Modified

2024-11-21T06:05:33.440

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 6.8 (MEDIUM)

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-772
Type: Primary
CWE-772

Affected Vendors & Products

Type	Vendor	Product	Version/Range	Vulnerable?
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	17.3	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	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	18.1	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	18.2	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	18.3	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	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	19.1	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	19.2	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	19.2	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
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	19.4	Yes
Operating System	juniper	junos	19.4	Yes
Operating System	juniper	junos	19.4	Yes
Operating System	juniper	junos	19.4	Yes
Operating System	juniper	junos	19.4	Yes
Operating System	juniper	junos	19.4	Yes
Operating System	juniper	junos	19.4	Yes
Operating System	juniper	junos	19.4	Yes
Operating System	juniper	junos	19.4	Yes
Operating System	juniper	junos	19.4	Yes
Operating System	juniper	junos	19.4	Yes
Operating System	juniper	junos	19.4	Yes
Operating System	juniper	junos	19.4	Yes
Operating System	juniper	junos	20.1	Yes
Operating System	juniper	junos	20.1	Yes
Operating System	juniper	junos	20.1	Yes
Operating System	juniper	junos	20.1	Yes
Operating System	juniper	junos	20.1	Yes
Operating System	juniper	junos	20.1	Yes
Operating System	juniper	junos	20.1	Yes
Operating System	juniper	junos	20.1	Yes
Operating System	juniper	junos	20.2	Yes
Operating System	juniper	junos	20.2	Yes
Operating System	juniper	junos	20.2	Yes
Operating System	juniper	junos	20.2	Yes
Operating System	juniper	junos	20.2	Yes
Operating System	juniper	junos	20.2	Yes
Operating System	juniper	junos	20.2	Yes
Operating System	juniper	junos	20.2	Yes
Operating System	juniper	junos	20.2	Yes
Operating System	juniper	junos	20.3	Yes
Operating System	juniper	junos	20.3	Yes
Operating System	juniper	junos	20.3	Yes
Operating System	juniper	junos	20.3	Yes
Operating System	juniper	junos	20.4	Yes
Operating System	juniper	junos	20.4	Yes
Operating System	juniper	junos	20.4	Yes
Operating System	juniper	junos	20.4	Yes
Operating System	juniper	junos	21.1	Yes
Operating System	juniper	junos	21.1	Yes

References

https://kb.juniper.net/JSA11246 Patch, Vendor Advisory ([email protected])
https://www.juniper.net/documentation/us/en/software/junos/subscriber-mgmt-sessions/topics/topic-map/general-authentication-service-events-tracing.html Product, Vendor Advisory ([email protected])
https://kb.juniper.net/JSA11246 Patch, Vendor Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://www.juniper.net/documentation/us/en/software/junos/subscriber-mgmt-sessions/topics/topic-map/general-authentication-service-events-tracing.html Product, 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.