6.5

CVE-2021-31363: juniper networks junos os Infinite Loop

CVSS: 6.5v3.1MediumModified
Published 19-10-2021Last modified 16-09-2024
Open JSON

Vulnerability summary

CVE-2021-31363 is a medium (CVSS 6.5) Infinite Loop vulnerability in juniper networks junos os. EPSS estimates a 0.40% chance of exploitation in the next 30 days, higher than 33.2% of scored vulnerabilities.

Overall risk
26/100
0100
Medium · default modelHow is this calculated?
CVSS score
6.5/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.40%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 19-10-2021
    PublishedVulnerability first disclosed.
  2. 16-09-2024
    Last modifiedVulnerability information updated.

Description

In an MPLS P2MP environment a Loop with Unreachable Exit Condition vulnerability in the routing protocol daemon (RPD) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated adjacent attacker to cause high load on RPD which in turn may lead to routing protocol flaps. If a system with sensor-based-stats enabled receives a specific LDP FEC this can lead to the above condition. Continued receipted of such an LDP FEC will create a sustained Denial of Service (DoS) condition. This issue affects: Juniper Networks Junos OS 19.2 version 19.2R2 and later versions prior to 19.2R3-S3; 19.3 versions prior to 19.3R2-S6, 19.3R3-S2; 19.4 versions prior to 19.4R1-S4, 19.4R2-S4, 19.4R3-S2; 20.1 versions prior to 20.1R2-S1, 20.1R3; 20.2 versions prior to 20.2R2-S1, 20.2R3; 20.3 versions prior to 20.3R1-S2, 20.3R2. This issue does not affect Juniper Networks Junos OS versions prior to 19.2R2. Juniper Networks Junos OS Evolved All versions prior to 20.1R2-S3-EVO; 20.3 versions prior to 20.3R1-S2-EVO.

CVSS metrics

3 scores · 2 sources · 2 versions

EPSS trend

Probability

0.40%

Chance of exploitation in the next 30 days

Percentile

33%

Versus all other CVEs

30-day change

0.00 pp

From 0.40% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.40%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Juniper2 products
  • junos19.2: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-s2 | 19.4:r1 | 19.4:r1-s1 | 19.4:r1-s2 | 19.4:r1-s3 | 19.4:r2-s4 | 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:r3 | 20.2:r1 | 20.2:r1-s1 | 20.2:r1-s2 | 20.2:r1-s3 | 20.2:r2 | 20.2:r3 | 20.3:r1 | 20.3:r1-s1 | 20.3:r2
  • junos_os_evolved20.1:r1 | 20.1:r1-s1 | 20.1:r2 | 20.1:r2-s1 | 20.1:r2-s2 | 20.2:r1 | 20.2:r1-s1 | 20.2:r2 | 20.3:r1 | 20.3:r1-s1
Juniper networks2 products
  • junos os≥ 19.2R2, < 19.2* | ≥ 19.3, < 19.3R2-S6, 19.3R3-S2 | ≥ 19.4, < 19.4R1-S4, 19.4R2-S4, 19.4R3-S2 | ≥ 20.1, < 20.1R2-S1, 20.1R3 | ≥ 20.2, < 20.2R2-S1, 20.2R3 | ≥ 20.3, < 20.3R1-S2, 20.3R2
  • junos os evolved≥ unspecified, < 20.1R2-S3-EVO | ≥ 20.3, < 20.3R1-S2-EVO

2 vendors · 4 products

References

1 links