Vulnerability Monitor

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CVE-2021-0208

An improper input validation vulnerability in the Routing Protocol Daemon (RPD) service of Juniper Networks Junos OS allows an attacker to send a malformed RSVP packet when bidirectional LSPs are in use, which when received by an egress router crashes the RPD causing a Denial of Service (DoS) condition. Continued receipt of the packet will sustain the Denial of Service. This issue affects: Juniper Networks Junos OS: All versions prior to 17.3R3-S10 except 15.1X49-D240 for SRX series; 17.4 versions prior to 17.4R3-S2; 18.1 versions prior to 18.1R3-S10; 18.2 versions prior to 18.2R2-S7, 18.2R3-S4; 18.3 versions prior to 18.3R3-S2; 18.4 versions prior to 18.4R1-S8, 18.4R2-S6, 18.4R3-S2; 19.1 versions prior to 19.1R1-S5, 19.1R3-S3; 19.2 versions prior to 19.2R3; 19.3 versions prior to 19.3R2-S5, 19.3R3; 19.4 versions prior to 19.4R2-S2, 19.4R3-S1; 20.1 versions prior to 20.1R1-S4, 20.1R2; 15.1X49 versions prior to 15.1X49-D240 on SRX Series. Juniper Networks Junos OS Evolved: 19.3 versions prior to 19.3R2-S5-EVO; 19.4 versions prior to 19.4R2-S2-EVO; 20.1 versions prior to 20.1R1-S4-EVO.

Security Impact Summary

This vulnerability carries a HIGH severity rating with a CVSS v3.1 score of 8.8, indicating it requires adjacent network access with relatively low complexity without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts confidentiality (data exposure), integrity (unauthorized modifications), and availability (service disruption) for affected systems. Impacting 15 products from juniper, from juniper, from juniper and 12 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

2021-01-15T18:15:14.947

Last Modified

2026-06-17T03:29:29.383

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 8.8 (HIGH)

CVSSv2 Vector

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

Access Vector: ADJACENT_NETWORK
Access Complexity: LOW
Authentication: NONE
Confidentiality Impact: NONE
Integrity Impact: NONE
Availability Impact: PARTIAL

Exploitability Score

6.5

Impact Score

2.9

Weaknesses

Type: Secondary
CWE-20
Type: Primary
CWE-20

Affected Vendors & Products

Type	Vendor	Product	Version/Range	Vulnerable?
Operating System	juniper	junos	15.1x49	Yes
Operating System	juniper	junos	15.1x49	Yes
Operating System	juniper	junos	15.1x49	Yes
Operating System	juniper	junos	15.1x49	Yes
Operating System	juniper	junos	15.1x49	Yes
Operating System	juniper	junos	15.1x49	Yes
Operating System	juniper	junos	15.1x49	Yes
Operating System	juniper	junos	15.1x49	Yes
Operating System	juniper	junos	15.1x49	Yes
Operating System	juniper	junos	15.1x49	Yes
Operating System	juniper	junos	15.1x49	Yes
Operating System	juniper	junos	15.1x49	Yes
Operating System	juniper	junos	15.1x49	Yes
Operating System	juniper	junos	15.1x49	Yes
Operating System	juniper	junos	15.1x49	Yes
Operating System	juniper	junos	15.1x49	Yes
Operating System	juniper	junos	15.1x49	Yes
Operating System	juniper	junos	15.1x49	Yes
Operating System	juniper	junos	15.1x49	Yes
Operating System	juniper	junos	15.1x49	Yes
Operating System	juniper	junos	15.1x49	Yes
Operating System	juniper	junos	15.1x49	Yes
Operating System	juniper	junos	15.1x49	Yes
Operating System	juniper	junos	15.1x49	Yes
Operating System	juniper	junos	15.1x49	Yes
Operating System	juniper	junos	15.1x49	Yes
Operating System	juniper	junos	15.1x49	Yes
Operating System	juniper	junos	15.1x49	Yes
Operating System	juniper	junos	15.1x49	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
Hardware	juniper	srx1500	-	No
Hardware	juniper	srx300	-	No
Hardware	juniper	srx320	-	No
Hardware	juniper	srx340	-	No
Hardware	juniper	srx345	-	No
Hardware	juniper	srx380	-	No
Hardware	juniper	srx4100	-	No
Hardware	juniper	srx4200	-	No
Hardware	juniper	srx4600	-	No
Hardware	juniper	srx5400	-	No
Hardware	juniper	srx550	-	No
Hardware	juniper	srx5600	-	No
Hardware	juniper	srx5800	-	No
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	18.2	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	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	19.2	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	19.4	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_os_evolved	19.3	Yes
Operating System	juniper	junos_os_evolved	19.3	Yes
Operating System	juniper	junos_os_evolved	19.4	Yes
Operating System	juniper	junos_os_evolved	19.4	Yes
Operating System	juniper	junos_os_evolved	19.4	Yes
Operating System	juniper	junos_os_evolved	20.1	Yes
Operating System	juniper	junos_os_evolved	20.1	Yes
Operating System	juniper	junos_os_evolved	20.1	Yes

References

https://kb.juniper.net/JSA11098 Vendor Advisory ([email protected])
https://www.juniper.net/documentation/en_US/junos/topics/reference/configuration-statement/corouted-bidirectional-edit-protocols-mpls.html Vendor Advisory ([email protected])
https://www.juniper.net/documentation/en_US/junos/topics/reference/configuration-statement/disable-edit-protocols-rsvp.html Vendor Advisory ([email protected])
https://kb.juniper.net/JSA11098 Vendor Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://www.juniper.net/documentation/en_US/junos/topics/reference/configuration-statement/corouted-bidirectional-edit-protocols-mpls.html Vendor Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://www.juniper.net/documentation/en_US/junos/topics/reference/configuration-statement/disable-edit-protocols-rsvp.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.