CVE-2021-0297: Junos OS Evolved: BGP and LDP sessions with TCP MD5 authentication established with peers not configured for authentication

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.7% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-10-19 · updated 2026-06-17
Weakness: CWE-755

Description

A vulnerability in the processing of TCP MD5 authentication in Juniper Networks Junos OS Evolved may allow a BGP or LDP session configured with MD5 authentication to succeed, even if the peer does not have TCP MD5 authentication enabled. This could lead to untrusted or unauthorized sessions being established, resulting in an impact on confidentiality or stability of the network. This issue affects Juniper Networks Junos OS Evolved: All versions prior to 20.3R2-S1-EVO; 20.4 versions prior to 20.4R2-EVO; 21.1 versions prior to 21.1R2-EVO. Juniper Networks Junos OS is not affected by this issue.

Affected products

Juniper Networks Junos OS Evolved: 20.3-r1, 20.3-r1-s1, 20.3-r2, 20.4-r1, 21.1-r1

References

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