Security readout for executives and security teams
Plain-English summary
This issue can let an unauthenticated network attacker disrupt traffic on vulnerable Juniper Junos OS Evolved systems. Specially crafted packets can crash and restart the forwarding toolkit manager process, impacting all traffic through the affected FPC. Repeated packets can sustain a denial-of-service condition.
Executive priority
Treat as high priority for vulnerable Junos OS Evolved infrastructure. This is an availability risk, not a data-theft issue, but it can interrupt business traffic if affected devices process malicious packet flows.
Technical view
CVE-2021-0286 is CWE-703 exceptional-condition handling in Junos OS Evolved. Crafted packets can crash evo-aftmand-bt or evo-aftmand-zx, causing process restart and FPC traffic impact. CVSS 3.1 is 7.5, network reachable, low complexity, no privileges or user interaction, availability-only impact.
Likely exposure
Exposure is limited to Juniper Networks Junos OS Evolved releases before 20.4R2-EVO and 21.1 releases before 21.1R2-EVO. The source bundle does not identify other affected Juniper products or platforms.
Exploitation context
The CVE is not listed as CISA KEV in the supplied data, and no cited source states active exploitation. The risk is still operationally significant because network-reachable unauthenticated packets can cause forwarding-plane service disruption.
Researcher notes
The source names process crashes, example log messages, affected version boundaries, and CVSS vector. It does not provide packet format, proof-of-concept status, workaround details, or evidence of exploitation. Avoid assuming impact beyond Junos OS Evolved and affected releases.
Mitigation direction
- Upgrade affected systems to 20.4R2-EVO, 21.1R2-EVO, or later fixed releases.
- Review Juniper advisory JSA11188 for current vendor guidance and upgrade details.
- Prioritize systems carrying critical or externally reachable traffic paths.
- Prepare maintenance and rollback planning before upgrading production forwarding infrastructure.
Validation and detection
- Inventory Junos OS Evolved versions across all relevant devices.
- Confirm no device remains below 20.4R2-EVO or 21.1R2-EVO.
- Check logs for evo-aftmand-bt or evo-aftmand-zx crash messages.
- Review FPC traffic disruption incidents for matching timestamps and process restarts.
- After remediation, verify stable forwarding and absence of repeated AFT manager crashes.
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
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-703: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-0286 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
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/JSA11188CVE 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 or Handling of Exceptional Conditions
Improper Check or Handling of Exceptional Conditions represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.