CVE-2021-0256

Junos OS: mosquitto Local Privilege Escalation vulnerability in SUID binaries

Published Apr 22, 2021 CVSS 3.1 · 5.5 Medium EPSS < 1% KEV · Not listed
Description
A sensitive information disclosure vulnerability in the mosquitto message broker of Juniper Networks Junos OS may allow a locally authenticated user with shell access the ability to read portions of sensitive files, such as the master.passwd file. Since mosquitto is shipped with setuid permissions enabled and is owned by the root user, this vulnerability may allow a local privileged user the ability to run mosquitto with root privileges and access sensitive information stored on the local filesystem. This issue affects Juniper Networks Junos OS: 17.3 versions prior to 17.3R3-S12, 17.4 versions prior to 17.4R3-S4; 18.1 versions prior to 18.1R3-S12; 18.3 versions prior to 18.3R3-S4; 19.1 versions prior to 19.1R3-S4; 19.3 versions prior to 19.3R3-S1, 19.3R3-S2; 19.4 versions prior to 19.4R2-S3; 20.1 versions prior to 20.1R2; 20.2 versions prior to 20.2R1-S3, 20.2R2, 20.2R3.

Remediation

Vendor Solution

The following software releases have been updated to resolve this specific issue: Junos OS 17.3R3-S12, 17.4R3-S4, 18.1R3-S12, 19.1R3-S4, 19.3R3-S1, 19.3R3-S2, 19.4R2-S3, 20.1R2, 20.2R1-S3, 20.2R2, 20.2R3, 20.3R1, and all subsequent releases.


Vendor Workaround

Use access lists or firewall filters to limit access to the device only from trusted hosts. Limit shell access to only trusted system administrators.

Tracking

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Advisories

Source ID Title
EUVD EUVD EUVD-2021-2875 A sensitive information disclosure vulnerability in the mosquitto message broker of Juniper Networks Junos OS may allow a locally authenticated user with shell access the ability to read portions of sensitive files, such as the master.passwd file. Since mosquitto is shipped with setuid permissions enabled and is owned by the root user, this vulnerability may allow a local privileged user the ability to run mosquitto with root privileges and access sensitive information stored on the local filesystem. This issue affects Juniper Networks Junos OS: 17.3 versions prior to 17.3R3-S12, 17.4 versions prior to 17.4R3-S4; 18.1 versions prior to 18.1R3-S12; 18.3 versions prior to 18.3R3-S4; 19.1 versions prior to 19.1R3-S4; 19.3 versions prior to 19.3R3-S1, 19.3R3-S2; 19.4 versions prior to 19.4R2-S3; 20.1 versions prior to 20.1R2; 20.2 versions prior to 20.2R1-S3, 20.2R2, 20.2R3.
References
History

No history.

Weaknesses

Sources

Status
PUBLISHED
Assigner
juniper
Published
Updated
Sep 16, 2024, 7:10 PM
Reserved
Oct 27, 2020, 12:00 AM
Status
Modified
Published
Apr 22, 2021, 8:15 PM
Modified
Jun 17, 2026, 3:29 AM