Session Smart Router: Authentication Bypass Vulnerability

published 2021-10-19 5y ago modified 2026-06-17 4mo ago also EUVD-2021-18259

cvss: 9.8; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 1.7%; EPSS 1.7% chance of exploitation in 30 days, percentile 77%
public exploits: 0; none known

The usage of an internal HTTP header created an authentication bypass vulnerability (CWE-287), allowing an attacker to view internal files, change settings, manipulate services and execute arbitrary code. This issue affects all Juniper Networks 128 Technology Session Smart Router versions prior to 4.5.11, and all versions of 5.0 up to and including 5.0.1.

Patch / fix

fixed in 1

Juniper Networks 128 Technology Session Smart Router 4.5.11

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Exploit prediction

1.72% chance of exploitation in the next 30 days, higher than 77% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by	version	score	vector
CNA	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD	2.0	7.5	AV:N/AC:L/Au:N/C:P/I:P/A:P

Affected products

Juniper Networks 128 Technology Session Smart Router

Classification

Weakness

CWE-287 Improper Authentication

References

kb.juniper.net /JSA11256
vendor-advisory

Sources

CVE List CVE-2021-31349
NVD CVE-2021-31349

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