Unchecked Return Value in MX Series and Junos OS - CVE-2021-31366
Published: October 14, 2021
Vulnerability identifier: #VU57356
CSH Severity: Low
CVSS v4: 7.1 [CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2021-31366
CWE-ID: CWE-252
Exploitation vector: Adjecent network
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to unchecked return value in the authd (authentication daemon). A remote attacker on the local network can send a specific username and perform a denial of service (DoS) attack.
Affected software
MX Series
Junos OS
Junos OS
How to mitigate CVE-2021-31366
Install updates from vendor's website.
Junos OS - addressed in versions 15.1R7-S9, 17.3R3-S12, 17.4R3-S5, 18.1R3-S13, 18.2R3-S8, 18.3R3-S5, 18.4R3-S9, 19.1R3-S6, 19.2R1-S7, 19.2R3-S3, 19.3R2-S6, 19.3R3-S3, 19.4R3-S3, 20.1R3, 20.2R3-S1, 20.3R3, 20.4R3, 21.1R2, 21.2R1