Security readout for executives and security teams
Plain-English summary
Certain Juniper Junos OS routers can crash their routing daemon when they process a malformed or unusual BGP UPDATE while Multipath or add-path is enabled. Repeated messages can keep routing unstable, creating a denial-of-service risk for affected networks.
Executive priority
Treat as high priority for networks relying on Juniper BGP routing. The main business risk is routing instability or outage, especially if vulnerable peers repeatedly receive the triggering UPDATE.
Technical view
CVE-2021-0282 affects Junos OS releases 12.3 through 19.1 before specified fixed builds. With BGP Multipath or add-path enabled, a specific BGP UPDATE can crash and restart RPD. The issue applies to IBGP and EBGP over IPv4 or IPv6, and the UPDATE may propagate to vulnerable peers.
Likely exposure
Exposure is limited to Junos OS devices running affected versions with BGP Multipath or add-path enabled. Devices without those features enabled are stated as not affected.
Exploitation context
The CVE has CVSS 7.5 with network attack vector and no privileges or user interaction. The provided bundle does not show CISA KEV listing or cited evidence of active exploitation.
Researcher notes
Focus assessment on BGP-enabled Junos routers where Multipath or add-path is configured. The source describes daemon crash and restart behavior, sustained DoS from repeated processing, and possible propagation to other vulnerable BGP peers.
Mitigation direction
- Upgrade Junos OS to a fixed release listed by Juniper.
- Disable BGP Multipath or add-path where operationally acceptable.
- Review Juniper JSA11186 for vendor-supported remediation guidance.
- Prioritize internet-facing EBGP and core IBGP routers first.
Validation and detection
- Inventory Junos OS versions across routing infrastructure.
- Check BGP configurations for Multipath or add-path enablement.
- Confirm devices meet or exceed the fixed Junos OS releases.
- Review logs for RPD crashes, restarts, and BGP instability.
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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CWE-754: Exact CWE lookup
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Open ATT&CK lookupCVE-2021-0282 mapping review
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Open ATT&CK lookup- Severity
- High
- CVSS
- 7.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/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:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://kb.juniper.net/JSA11186CVE 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.