CVE-2021-28510

Summary

For certain systems running EOS, a Precision Time Protocol (PTP) packet of a management/signaling message with an invalid Type-Length-Value (TLV) causes the PTP agent to restart. Repeated restarts of the service will make the service unavailable.

Affected Software

VendorProductVersion RangeStatus
Arista NetworksEOS4.22affected
Arista NetworksEOS4.27.1 <= 4.27.0affected
Arista NetworksEOS4.26.4 <= 4.26.0affected
Arista NetworksEOS4.25.6 <= 4.25.0affected
Arista NetworksEOS4.24.8 <= 4.24.0affected
Arista NetworksEOS4.23.10 <= 4.23.0affected

Weaknesses

  • CWE-400: CWE-400 Uncontrolled Resource Consumption

Workarounds

Install ACL rules to drop PTP packets from untrusted sources. Best practice is to block access to untrusted (non-management) networks.

ADP Enrichment

CVE Program Container

Additional References

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: poc
    • Automatable: yes
    • Technical Impact: partial

References