Privilege escalation in Juniper Junos
CVE-2021-0256
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.
EPSS: 0.002 (11.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.
Affected products
- Juniper Junos — versions 17.3, 17.4, 18.1
- Juniper Networks Junos Os — versions 17.3, 17.4, 18.1
Weakness classification (CWE)
Public proof-of-concept exploits
References
- sirt@juniper.net (x_refsource_MISC, Vendor Advisory)
Frequently asked questions
- What is CVE-2021-0256?
- CVE-2021-0256 is a medium-severity vulnerability in Juniper Junos, classified under CWE-250. CVSS score: 5.5/10. Published 2021-04-22.
- How severe is CVE-2021-0256?
- Medium severity. CVSS v3 base score is 5.5 out of 10.
- Is CVE-2021-0256 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.