CVE-2021-0258: juniper networks junos os Race Condition
Vulnerability summary
CVE-2021-0258 is a high (CVSS 7.1) Race Condition vulnerability in juniper networks junos os. EPSS estimates a 0.65% chance of exploitation in the next 30 days, higher than 50% of scored vulnerabilities.
Timeline
- 22-04-2021PublishedVulnerability first disclosed.
- 16-09-2024Last modifiedVulnerability information updated.
Description
A vulnerability in the forwarding of transit TCPv6 packets received on the Ethernet management interface of Juniper Networks Junos OS allows an attacker to trigger a kernel panic, leading to a Denial of Service (DoS). Continued receipt and processing of these transit packets will create a sustained Denial of Service (DoS) condition. This issue only occurs when TCPv6 packets are routed through the management interface. Other transit traffic, and traffic destined to the management interface, are unaffected by this vulnerability. This issue was introduced as part of a TCP Parallelization feature added in Junos OS 17.2, and affects systems with concurrent network stack enabled. This feature is enabled by default, but can be disabled (see WORKAROUND section below). This issue affects Juniper Networks Junos OS: 17.2 versions prior to 17.2R3-S4; 17.3 versions prior to 17.3R3-S9; 17.4 versions prior to 17.4R2-S11, 17.4R3-S2; 18.1 versions prior to 18.1R3-S11; 18.2 versions prior to 18.2R3-S5; 18.3 versions prior to 18.3R2-S4, 18.3R3-S3; 18.4 versions prior to 18.4R2-S5, 18.4R3-S4; 19.1 versions prior to 19.1R2-S2, 19.1R3; 19.2 versions prior to 19.2R1-S5, 19.2R2; 19.3 versions prior to 19.3R2-S4, 19.3R3; 19.4 versions prior to 19.4R1-S3, 19.4R2. This issue does not affect Juniper Networks Junos OS versions prior to 17.2R1.
CVSS metrics
3 scores · 2 sources · 2 versions- NVDNIST5.9MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.65%
Chance of exploitation in the next 30 days
Percentile
50%
Versus all other CVEs
30-day change
0.00 pp
From 0.65% 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
Juniper1 product
- junos17.2 | 17.2:r1 | 17.2:r1-s1 | 17.2:r1-s2 | 17.2:r1-s3 | 17.2:r1-s4 | 17.2:r1-s5 | 17.2:r1-s6 | 17.2:r1-s7 | 17.2:r1-s8 | 17.2:r2 | 17.2:r2-s11 | 17.2:r2-s4 | 17.2:r2-s6 | 17.2:r2-s7 | 17.2:r3 | 17.2:r3-s1 | 17.2:r3-s2 | 17.2:r3-s3 | 17.3 | 17.3:r1 | 17.3:r1-s1 | 17.3:r1-s4 | 17.3:r2 | 17.3:r2-s1 | 17.3:r2-s2 | 17.3:r2-s3 | 17.3:r2-s4 | 17.3:r2-s5 | 17.3:r3 | 17.3:r3-s1 | 17.3:r3-s10 | 17.3:r3-s2 | 17.3:r3-s3 | 17.3:r3-s4 | 17.3:r3-s5 | 17.3:r3-s6 | 17.3:r3-s7 | 17.3:r3-s8 | 17.4 | 17.4:r1 | 17.4:r1-s1 | 17.4:r1-s2 | 17.4:r1-s3 | 17.4:r1-s4 | 17.4:r1-s5 | 17.4:r1-s6 | 17.4:r1-s7 | 17.4:r2 | 17.4:r2-s1 | 17.4:r2-s10 | 17.4:r2-s2 | 17.4:r2-s3 | 17.4:r2-s4 | 17.4:r2-s5 | 17.4:r2-s6 | 17.4:r2-s7 | 17.4:r2-s8 | 17.4:r2-s9 | 17.4:r3 | 17.4:r3-s1 | 18.1 | 18.1:r1 | 18.1:r2 | 18.1:r2-s1 | 18.1:r2-s2 | 18.1:r2-s4 | 18.1:r3 | 18.1:r3-s1 | 18.1:r3-s10 | 18.1:r3-s2 | 18.1:r3-s3 | 18.1:r3-s4 | 18.1:r3-s5 | 18.1:r3-s6 | 18.1:r3-s7 | 18.1:r3-s8 | 18.1:r3-s9 | 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 | 18.3 | 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:r3 | 18.3:r3-s1 | 18.3:r3-s2 | 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:r3 | 18.4:r3-s1 | 18.4:r3-s2 | 18.4:r3-s3 | 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:r2 | 19.1:r2-s1 | 19.2 | 19.2:r1 | 19.2:r1-s1 | 19.2:r1-s2 | 19.2:r1-s3 | 19.2:r1-s4 | 19.3 | 19.3:r1 | 19.3:r1-s1 | 19.3:r2 | 19.3:r2-s1 | 19.3:r2-s2 | 19.3:r2-s3 | 19.4:r1 | 19.4:r1-s1 | 19.4:r1-s2
Juniper networks1 product
- junos os≥ 17.3, < 17.3R3-S9 | ≥ 17.4, < 17.4R2-S11, 17.4R3-S2 | ≥ 18.1, < 18.1R3-S11 | ≥ 18.2, < 18.2R3-S5 | ≥ 18.3, < 18.3R2-S4, 18.3R3-S3 | ≥ 18.4, < 18.4R2-S5, 18.4R3-S4 | ≥ 19.1, < 19.1R2-S2, 19.1R3 | ≥ 19.2, < 19.2R1-S5, 19.2R2 | ≥ 19.3, < 19.3R2-S4, 19.3R3 | ≥ 19.4, < 19.4R1-S3, 19.4R2
2 vendors · 2 products