Attacker Value
Unknown
(0 users assessed)
Exploitability
Unknown
(0 users assessed)
User Interaction
None
Privileges Required
None
Attack Vector
Network
0

CVE-2021-31378

Disclosure Date: October 13, 2021
Add MITRE ATT&CK tactics and techniques that apply to this CVE.

Description

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.

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CVSS V3 Severity and Metrics
Base Score:
7.5 High
Impact Score:
3.6
Exploitability Score:
3.9
Vector:
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector (AV):
Network
Attack Complexity (AC):
Low
Privileges Required (PR):
None
User Interaction (UI):
None
Scope (S):
Unchanged
Confidentiality (C):
None
Integrity (I):
None
Availability (A):
High

General Information

Vendors

  • juniper

Products

  • junos 17.3,
  • junos 17.4,
  • junos 18.1,
  • junos 18.2,
  • junos 18.3,
  • junos 18.4,
  • junos 19.1,
  • junos 19.2,
  • junos 19.3,
  • junos 19.4,
  • junos 20.1,
  • junos 20.2,
  • junos 20.3,
  • junos 20.4,
  • junos 21.1

Additional Info

Technical Analysis