CVE-2021-31362: juniper networks junos os Protection Mechanism Failure
Vulnerability summary
CVE-2021-31362 is a medium (CVSS 6.5) Protection Mechanism Failure vulnerability in juniper networks junos os. EPSS estimates a 0.42% chance of exploitation in the next 30 days, higher than 35.2% of scored vulnerabilities.
Timeline
- 19-10-2021PublishedVulnerability first disclosed.
- 17-09-2024Last modifiedVulnerability information updated.
Description
A Protection Mechanism Failure vulnerability in RPD (routing protocol daemon) of Juniper Networks Junos OS and Junos OS Evolved allows an adjacent unauthenticated attacker to cause established IS-IS adjacencies to go down by sending a spoofed hello PDU leading to a Denial of Service (DoS) condition. Continued receipted of these spoofed PDUs will create a sustained Denial of Service (DoS) condition. This issue affects: Juniper Networks Junos OS All versions prior to 18.2R3-S8; 18.3 versions prior to 18.3R3-S5; 18.4 versions prior to 18.4R3-S9; 19.1 versions prior to 19.1R3-S7; 19.2 versions prior to 19.2R1-S7, 19.2R3-S3; 19.3 versions prior to 19.3R2-S6, 19.3R3-S2; 19.4 versions prior to 19.4R3-S3; 20.1 versions prior to 20.1R3; 20.2 versions prior to 20.2R3; 20.3 versions prior to 20.3R3; 20.4 versions prior to 20.4R2. Juniper Networks Junos OS Evolved All versions prior to 20.4R2-EVO; 21.1 versions prior to 21.1R2-EVO.
CVSS metrics
3 scores · 2 sources · 2 versions- NVDNIST6.5MediumCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.42%
Chance of exploitation in the next 30 days
Percentile
35%
Versus all other CVEs
30-day change
0.00 pp
From 0.42% on 20-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Juniper2 products
- junos≤ 18.1 | 18.2 | 18.2:r1 | 18.2:r1-s2 | 18.2:r1-s3 | 18.2:r1-s4 | 18.2:r1-s5 | 18.2:r2 | 18.2:r2-s1 | 18.2:r2-s2 | 18.2:r2-s3 | 18.2:r2-s4 | 18.2:r2-s5 | 18.2:r2-s6 | 18.2:r2-s7 | 18.2:r3 | 18.2:r3-s1 | 18.2:r3-s2 | 18.2:r3-s3 | 18.2:r3-s4 | 18.2:r3-s5 | 18.2:r3-s6 | 18.2:r3-s7 | 18.3 | 18.3:r1 | 18.3:r1-s1 | 18.3:r1-s2 | 18.3:r1-s3 | 18.3:r1-s4 | 18.3:r1-s5 | 18.3:r1-s6 | 18.3:r2 | 18.3:r2-s1 | 18.3:r2-s2 | 18.3:r2-s3 | 18.3:r2-s4 | 18.3:r3 | 18.3:r3-s1 | 18.3:r3-s2 | 18.3:r3-s3 | 18.3:r3-s4 | 18.4 | 18.4:r1 | 18.4:r1-s1 | 18.4:r1-s2 | 18.4:r1-s3 | 18.4:r1-s4 | 18.4:r1-s5 | 18.4:r1-s6 | 18.4:r1-s7 | 18.4:r2 | 18.4:r2-s1 | 18.4:r2-s2 | 18.4:r2-s3 | 18.4:r2-s4 | 18.4:r2-s5 | 18.4:r2-s6 | 18.4:r2-s7 | 18.4:r2-s8 | 18.4:r3 | 18.4:r3-s1 | 18.4:r3-s2 | 18.4:r3-s3 | 18.4:r3-s4 | 18.4:r3-s5 | 18.4:r3-s6 | 18.4:r3-s7 | 18.4:r3-s8 | 19.1 | 19.1:r1 | 19.1:r1-s1 | 19.1:r1-s2 | 19.1:r1-s3 | 19.1:r1-s4 | 19.1:r1-s5 | 19.1:r1-s6 | 19.1:r2 | 19.1:r2-s1 | 19.1:r2-s2 | 19.1:r3 | 19.1:r3-s1 | 19.1:r3-s2 | 19.1:r3-s3 | 19.1:r3-s4 | 19.1:r3-s5 | 19.1:r3-s6 | 19.2 | 19.2:r1 | 19.2:r1-s1 | 19.2:r1-s2 | 19.2:r1-s3 | 19.2:r1-s4 | 19.2:r1-s5 | 19.2:r1-s6 | 19.2:r2 | 19.2:r2-s1 | 19.2:r3 | 19.2:r3-s1 | 19.2:r3-s2 | 19.3 | 19.3:r1 | 19.3:r1-s1 | 19.3:r2 | 19.3:r2-s1 | 19.3:r2-s2 | 19.3:r2-s3 | 19.3:r2-s4 | 19.3:r2-s5 | 19.3:r3 | 19.3:r3-s1 | 19.4:r1 | 19.4:r1-s1 | 19.4:r1-s2 | 19.4:r1-s3 | 19.4:r1-s4 | 19.4:r2 | 19.4:r2-s1 | 19.4:r2-s2 | 19.4:r2-s3 | 19.4:r2-s4 | 19.4:r3 | 19.4:r3-s1 | 19.4:r3-s2 | 20.1:r1 | 20.1:r1-s1 | 20.1:r1-s2 | 20.1:r1-s3 | 20.1:r1-s4 | 20.1:r2 | 20.1:r2-s1 | 20.1:r2-s2 | 20.2:r1 | 20.2:r1-s1 | 20.2:r1-s2 | 20.2:r1-s3 | 20.2:r2 | 20.2:r2-s1 | 20.2:r2-s2 | 20.2:r2-s3 | 20.3:r1 | 20.3:r1-s1 | 20.3:r2 | 20.3:r2-s1 | 20.4:r1 | 20.4:r1-s1
- junos_os_evolved≤ 20.3 | 20.4:r1 | 20.4:r1-s1 | 20.4:r1-s2 | 21.1 | 21.1:r1 | 21.1:r1-s1
Juniper networks2 products
- junos os≥ unspecified, < 18.2R3-S8 | ≥ 18.3, < 18.3R3-S5 | ≥ 18.4, < 18.4R3-S9 | ≥ 19.1, < 19.1R3-S7 | ≥ 19.2, < 19.2R1-S7, 19.2R3-S3 | ≥ 19.3, < 19.3R2-S6, 19.3R3-S2 | ≥ 19.4, < 19.4R3-S3 | ≥ 20.1, < 20.1R3 | ≥ 20.2, < 20.2R3 | ≥ 20.3, < 20.3R3 | ≥ 20.4, < 20.4R2
- junos os evolved≥ unspecified, < 20.4R2-EVO | ≥ 21.1, < 21.1R2-EVO
2 vendors · 4 products