On PTX Series and QFX10k Series devices with the "inline-jflow" feature enabled, a use after free weakness in the Packet Forwarding Engine (PFE) microkernel architecture of Juniper Networks Junos OS may allow an attacker to cause a Denial of Service (DoS) condition whereby one or more Flexible PIC Concentrators (FPCs) may restart. As this is a race condition situation this issue become more likely to be hit when network instability occurs, such as but not limited to BGP/IGP reconvergences, and/or further likely to occur when more active "traffic flows" are occurring through the device. When this issue occurs, it will cause one or more FPCs to restart unexpectedly. During FPC restarts core files will be generated. While the core file is generated traffic will be disrupted. Sustained receipt of large traffic flows and reconvergence-like situations may sustain the Denial of Service (DoS) situation. This issue affects: Juniper Networks Junos OS: 18.1 version 18.1R2 and later versions prior to 18.1R3-S10 on PTX Series, QFX10K Series.
CVE-2021-0270
This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 0.7%, top 50% 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
- 50.2%
- KEV
- Not listed
Published
April 22, 2021
Last Modified
November 21, 2024
References (4)
- sirt@juniperhttps://kb.juniper.net/JSA11161
- sirt@juniperhttps://www.juniper.net/documentation/en_US/junos/topics/task/configuration/inline-flow-monitoring-ptx.html
- af854a3a-2127-422b-91ae-364da2661108https://kb.juniper.net/JSA11161
- af854a3a-2127-422b-91ae-364da2661108https://www.juniper.net/documentation/en_US/junos/topics/task/configuration/inline-flow-monitoring-ptx.html
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 13× in last 7d / 48× 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.
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Related CVEs(same CWE)
Same CWE
10 shownCWE-416 · CWE-362
Frequently asked(5)
What is CVE-2021-0270?
When was CVE-2021-0270 disclosed?
Is CVE-2021-0270 actively exploited?
What is the CVSS score of CVE-2021-0270?
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Dependency Blast Radius
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