Vulnerability in Juniper Junos OS Evolved
CVE-2021-0239
In Juniper Networks Junos OS Evolved, receipt of a stream of specific genuine Layer 2 frames may cause the Advanced Forwarding Toolkit (AFT) manager process (Evo-aftmand), responsible for handling Route, Class-of-Service (CoS), Firewall operations within the packet forwarding engine (PFE) to crash and restart, leading to a Denial of Service (DoS) condition. By continuously sending this specific stream of genuine Layer 2 frames, an attacker can repeatedly crash the PFE, causing a sustained Denial of Service (DoS). This issue affects Juniper Networks Junos OS Evolved: All versions prior to 20.4R1-EVO. This issue does not affect Junos OS versions.
EPSS: 0.004 (30.7th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Juniper Junos_os_evolved — versions 20.4
- Juniper Networks Junos Os Evolved — versions unspecified
Weakness classification (CWE)
References
- sirt@juniper.net (x_refsource_MISC, Vendor Advisory)
Frequently asked questions
- What is CVE-2021-0239?
- CVE-2021-0239 is a medium-severity vulnerability in Juniper Junos OS Evolved, classified under Improper Check for Unusual or Exceptional Conditions. CVSS score: 6.5/10. Published 2021-04-22.
- How severe is CVE-2021-0239?
- Medium severity. CVSS v3 base score is 6.5 out of 10.