Junos OS: NFX Series, SRX Series: PFE may crash upon receipt of specific packet when SSL Proxy is configured.

published 2021-01-15 5y ago modified 2026-06-17 4mo ago also EUVD-2021-2825

cvss: 7.5; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 1.3%; EPSS 1.3% chance of exploitation in 30 days, percentile 71%
public exploits: 0; none known

A NULL Pointer Dereference vulnerability in Juniper Networks Junos OS allows an attacker to send a specific packet causing the packet forwarding engine (PFE) to crash and restart, resulting in a Denial of Service (DoS). By continuously sending these specific packets, an attacker can repeatedly disable the PFE causing a sustained Denial of Service (DoS). This issue only affects Juniper Networks NFX Series, SRX Series platforms when SSL Proxy is configured. This issue affects Juniper Networks Junos OS on NFX Series and SRX Series: 18.3 versions prior to 18.3R3-S4; 18.4 versions prior to 18.4R3-S1; 19.1 versions prior to 19.1R1-S6, 19.1R2-S2, 19.1R3; 19.2 versions prior to 19.2R1-S2, 19.2R2; 19.3 versions prior to 19.3R2. This issue does not affect Juniper Networks Junos OS versions on NFX Series and SRX Series prior to 18.3R1.

Patch / fix

fixed in 1

Juniper Networks Junos OS 18.3R3-S4, 18.4R3-S1, 19.1R1-S6, 19.1R2-S2, 19.1R3, 19.2R1-S2, 19.2R2, 19.3R2

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Exploit prediction

1.33% chance of exploitation in the next 30 days, higher than 71% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by	version	score	vector
CNA	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD	2.0	5.0	AV:N/AC:L/Au:N/C:N/I:N/A:P

Affected products

Juniper Networks Junos OS

Classification

Weakness

CWE-476 NULL Pointer Dereference

References

kb.juniper.net /JSA11096
vendor-advisory

Sources

CVE List CVE-2021-0206
NVD CVE-2021-0206

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