An Improper Handling of Exceptional Conditions vulnerability in the processing of a transit or directly received malformed IPv6 packet in Juniper Networks Junos OS results in a kernel crash, causing the device to restart, leading to a Denial of Service (DoS). Continued receipt and processing of this packet will create a sustained Denial of Service (DoS) condition. This issue only affects systems with IPv6 configured. Devices with only IPv4 configured are not vulnerable to this issue. This issue affects Juniper Networks Junos OS: 19.4 versions prior to 19.4R3; 20.1 versions prior to 20.1R2; 20.2 versions prior to 20.2R1-S1, 20.2R2. This issue does not affect Juniper Networks Junos OS versions prior to 19.4R1.
CVE-2021-0299
This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 1.0%, top 42% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
- High severity, but no confirmed exploitation yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 7.5
- EG Score
- 7.5(medium)
- EG Risk
- 39(Track)EG Risk 39/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity75% × 45%Exploitation1% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS
- 58.4%
- KEV
- Not listed
Published
October 19, 2021
Last Modified
November 21, 2024
References (2)
- sirt@juniperhttps://kb.juniper.net/JSA11213
- af854a3a-2127-422b-91ae-364da2661108https://kb.juniper.net/JSA11213
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 13× in last 7d / 49× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-23 01:56 UTCEG score recompute
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Related CVEs(same CWE)
Same CWE
10 shownCWE-755
- CVE-2009-5043EG 9.8CRITICAL
- CVE-2019-17195EG 9.8EPSS 95%CRITICAL
- CVE-2019-14431EG 9.8CRITICAL
- CVE-2019-12815EG 9.8EPSS 99%CRITICAL
- CVE-2019-6256EG 9.8CRITICAL
- CVE-2018-19991EG 9.8CRITICAL
- CVE-2017-2877EG 9.8CRITICAL
- CVE-2017-5638EG 9.8 KEVEPSS 100%CRITICAL
- CVE-2018-0155NVD 8.6EG 9.0 KEVEPSS 94%HIGH
- CVE-2019-14287EG 8.9EPSS 99%HIGH
Frequently asked(5)
What is CVE-2021-0299?
When was CVE-2021-0299 disclosed?
Is CVE-2021-0299 actively exploited?
What is the CVSS score of CVE-2021-0299?
How do I remediate CVE-2021-0299?
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2021-0299
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