CVE-2021-0225
Published: 22 April 2021
Summary
CVE-2021-0225 is a medium-severity Improper Check for Unusual or Exceptional Conditions (CWE-754) vulnerability in Juniper Junos Os Evolved. Its CVSS base score is 5.8 (Medium).
Operationally, ranked at the 40.4th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2021-2844
Vulnerability details
An Improper Check for Unusual or Exceptional Conditions in Juniper Networks Junos OS Evolved may cause the stateless firewall filter configuration which uses the action 'policer' in certain combinations with other options to not take effect. An administrator can use…
more
the following CLI command to see the failures with filter configuration: user@device> show log kfirewall-agent.log | match ERROR Jul 23 14:16:03 ERROR: filter not supported This issue affects Juniper Networks Junos OS Evolved: Versions 19.1R1-EVO and above prior to 20.3R1-S2-EVO, 20.3R2-EVO. This issue does not affect Juniper Networks Junos OS.
- CWE(s)
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Requires detection and response to audit logging failures as an unusual or exceptional condition.
Implements detection of unusual or exceptional conditions followed by safe mode entry, reducing the window for exploitation of unchecked conditions.
Training ensures users perform required checks for unusual or exceptional conditions as part of contingency roles, limiting attacker leverage from skipped validations.
IR testing directly validates checks for unusual or exceptional conditions that could indicate security incidents.
Requires ongoing monitoring of organization-defined metrics and analysis, enabling checks for unusual or exceptional conditions.
Security testing routinely checks for unusual or exceptional inputs/conditions, identifying missing validation steps that flaw remediation then resolves.
Requires detection of unusual conditions followed by a controlled transition to the defined failure state.
MTTF determination forces explicit checks for conditions that precede predictable component failure.