CVE-2024-21600

Summary

An Improper Neutralization of Equivalent Special Elements vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on PTX Series allows a unauthenticated, adjacent attacker to cause a Denial of Service (DoS).

When MPLS packets are meant to be sent to a flexible tunnel interface (FTI) and if the FTI tunnel is down, these will hit the reject NH, due to which the packets get sent to the CPU and cause a host path wedge condition. This will cause the FPC to hang and requires a manual restart to recover.

Please note that this issue specifically affects PTX1000, PTX3000, PTX5000 with FPC3, PTX10002-60C, and PTX10008/16 with LC110x. Other PTX Series devices and Line Cards (LC) are not affected.

The following log message can be seen when the issue occurs:

Cmerror Op Set: Host Loopback: HOST LOOPBACK WEDGE DETECTED IN PATH ID <id> (URI: /fpc/<fpc>/pfe/<pfe>/cm/<cm>/Host_Loopback/<cm>/HOST_LOOPBACK_MAKE_CMERROR_ID[<id>]) This issue affects Juniper Networks Junos OS:

  • All versions earlier than 20.4R3-S8;
  • 21.1 versions earlier than 21.1R3-S4;
  • 21.2 versions earlier than 21.2R3-S6;
  • 21.3 versions earlier than 21.3R3-S3;
  • 21.4 versions earlier than 21.4R3-S5;
  • 22.1 versions earlier than 22.1R2-S2, 22.1R3;
  • 22.2 versions earlier than 22.2R2-S1, 22.2R3.

Affected Software

VendorProductVersion RangeStatus
Juniper NetworksJunos OS0 < 20.4R3-S8affected
Juniper NetworksJunos OS21.1 < 21.1R3-S4affected
Juniper NetworksJunos OS21.2 < 21.2R3-S6affected
Juniper NetworksJunos OS21.3 < 21.3R3-S3affected
Juniper NetworksJunos OS21.4 < 21.4R3-S5affected
Juniper NetworksJunos OS22.1 < 22.1R2-S2, 22.1R3affected
Juniper NetworksJunos OS22.2 < 22.2R2-S1, 22.2R3affected

Weaknesses

  • CWE-76: CWE-76 Improper Neutralization of Equivalent Special Elements
  • Denial of Service (DoS)

Workarounds

The issue can be prevented by configuring a limit for reject packets via:

[ system ddos-protection protocols reject aggregate bandwidth 20 ]

ADP Enrichment

CVE Program Container

Additional References

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References