CVE-2021-0206: Junos OS: NFX Series, SRX Series: PFE may crash upon receipt of specific packet when SSL Proxy is configured.

Severity: medium (CVSS 5.0 v2.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-01-15 · updated 2026-06-17
Weakness: CWE-476

Description

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.

Affected products

Juniper Junos OS: 18.3, 18.3-r1, 18.3-r1-s1, 18.3-r1-s2, 18.3-r1-s3, 18.3-r1-s5 (+37)

References

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