Security readout for executives and security teams
Plain-English summary
This vulnerability can crash and restart the routing process on affected Juniper devices using BGP origin validation with RPKI. Repeated triggering can create sustained routing disruption, affecting network availability rather than data confidentiality or integrity.
Executive priority
Treat this as a network availability risk for routing infrastructure using RPKI origin validation. It is not marked as actively exploited in the provided sources, but affected edge or core routers should be upgraded through normal priority maintenance.
Technical view
CVE-2021-0281 affects Junos OS and Junos OS Evolved when BGP origin validation is configured with RPKI. A specific packet received from the RPKI cache server can cause rpd to crash and restart. The CVSS score is 5.9 with high availability impact and high attack complexity.
Likely exposure
Exposure is limited to affected Juniper Junos OS or Junos OS Evolved devices that have BGP origin validation using RPKI configured. Organizations without that feature enabled are not described as affected by the provided sources.
Exploitation context
The source bundle does not show CISA KEV listing or confirmed active exploitation. The issue requires receipt and processing of a specific packet from the RPKI cache server, and repeated receipt can sustain denial of service.
Researcher notes
The key condition is RPKI-enabled BGP origin validation. Validation should focus on version exposure, feature configuration, and rpd stability. The public description does not provide packet details or broader exploit prerequisites beyond receipt from the RPKI cache server.
Mitigation direction
- Upgrade affected Junos OS releases to the fixed maintenance releases listed by Juniper.
- Upgrade Junos OS Evolved to 20.4R2-S2-EVO or a later vendor-supported release.
- If upgrading is delayed, check Juniper guidance for supported temporary mitigations.
- Prioritize routers where RPKI origin validation supports critical BGP routing.
Validation and detection
- Inventory Juniper devices running Junos OS or Junos OS Evolved.
- Identify devices configured for BGP origin validation with RPKI.
- Compare installed versions against the affected and fixed release list.
- Review routing process crash or restart history for rpd availability impact.
- Confirm upgraded devices remain stable after RPKI cache interaction.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
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ATT&CK lookup starting points
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Open ATT&CK lookupCVE-2021-0281 mapping review
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Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.9 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H2.23.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.9MediumVector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://kb.juniper.net/JSA11185CVE reference · x_refsource_CONFIRM
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Check for Unusual or Exceptional Conditions
Improper Check for Unusual or Exceptional Conditions represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.