{"id":"CVE-2024-21600","aliases":["EUVD-2024-19248","GHSA-8f5g-v4g5-c448"],"status":"published","title":"Junos OS: PTX Series: In an FTI scenario MPLS packets hitting reject next-hop will cause a host path wedge condition","description":"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).\n\nWhen 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.\n\nPlease 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.\n\nThe following log message can be seen when the issue occurs:\n\nCmerror Op Set: Host Loopback: HOST LOOPBACK WEDGE DETECTED IN PATH ID \u003cid\u003e (URI: /fpc/\u003cfpc\u003e/pfe/\u003cpfe\u003e/cm/\u003ccm\u003e/Host_Loopback/\u003ccm\u003e/HOST_LOOPBACK_MAKE_CMERROR_ID[\u003cid\u003e])\nThis issue affects Juniper Networks Junos OS:\n\n\n\n  *  All versions earlier than 20.4R3-S8;\n  *  21.1 versions earlier than 21.1R3-S4;\n  *  21.2 versions earlier than 21.2R3-S6;\n  *  21.3 versions earlier than 21.3R3-S3;\n  *  21.4 versions earlier than 21.4R3-S5;\n  *  22.1 versions earlier than 22.1R2-S2, 22.1R3;\n  *  22.2 versions earlier than 22.2R2-S1, 22.2R3.","severity":{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00324,"percentile":0.25725,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-76"],"published":"2024-01-12T00:53:38Z","modified":"2026-06-17T07:09:48Z","products":[{"vendor":"juniper","product":"junos"},{"vendor":"juniper networks","product":"junos os"}],"references":[{"url":"https://supportportal.juniper.net/JSA75741","tags":["vendor-advisory","x_transferred","Vendor Advisory"]},{"url":"https://www.first.org/cvss/calculator/4.0#CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L","tags":["technical-description","x_transferred","Third Party Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2024-21600"},{"url":"https://github.com/advisories/GHSA-8f5g-v4g5-c448"}],"sources":{"cve":[{"id":"CVE-2024-21600","title":"Junos OS: PTX Series: In an FTI scenario MPLS packets hitting reject next-hop will cause a host path wedge condition","description":"\nAn 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).\n\nWhen 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.\n\nPlease 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.\n\nThe following log message can be seen when the issue occurs:\n\nCmerror Op Set: Host Loopback: HOST LOOPBACK WEDGE DETECTED IN PATH ID \u003cid\u003e (URI: /fpc/\u003cfpc\u003e/pfe/\u003cpfe\u003e/cm/\u003ccm\u003e/Host_Loopback/\u003ccm\u003e/HOST_LOOPBACK_MAKE_CMERROR_ID[\u003cid\u003e])\nThis issue affects Juniper Networks Junos OS:\n\n\n\n  *  All versions earlier than 20.4R3-S8;\n  *  21.1 versions earlier than 21.1R3-S4;\n  *  21.2 versions earlier than 21.2R3-S6;\n  *  21.3 versions earlier than 21.3R3-S3;\n  *  21.4 versions earlier than 21.4R3-S5;\n  *  22.1 versions earlier than 22.1R2-S2, 22.1R3;\n  *  22.2 versions earlier than 22.2R2-S1, 22.2R3.\n\n\n\n\n\n\n","status":"published","published":"2024-01-12T00:53:38.834Z","modified":"2025-06-17T21:09:19.373Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"cna"}],"cwes":["CWE-76"],"updated_at":"2026-11-02T14:34:05.077718Z"}],"euvd":[{"id":"EUVD-2024-19248","description":"\nAn 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).\n\nWhen 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.\n\nPlease 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.\n\nThe following log message can be seen when the issue occurs:\n\nCmerror Op Set: Host Loopback: HOST LOOPBACK WEDGE DETECTED IN PATH ID \u003cid\u003e (URI: /fpc/\u003cfpc\u003e/pfe/\u003cpfe\u003e/cm/\u003ccm\u003e/Host_Loopback/\u003ccm\u003e/HOST_LOOPBACK_MAKE_CMERROR_ID[\u003cid\u003e])\nThis issue affects Juniper Networks Junos OS:\n\n\n\n  *  All versions earlier than 20.4R3-S8;\n  *  21.1 versions earlier than 21.1R3-S4;\n  *  21.2 versions earlier than 21.2R3-S6;\n  *  21.3 versions earlier than 21.3R3-S3;\n  *  21.4 versions earlier than 21.4R3-S5;\n  *  22.1 versions earlier than 22.1R2-S2, 22.1R3;\n  *  22.2 versions earlier than 22.2R2-S1, 22.2R3.\n\n\n\n\n\n\n","status":"published","published":"2024-01-12T00:53:38Z","modified":"2025-06-17T21:09:19Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"medium"}],"updated_at":"2026-11-02T20:32:21.531807Z"}],"ghsa":[{"id":"GHSA-8f5g-v4g5-c448","title":"\nAn Improper Neutralization of Equivalent Special Elements vulnerability in the Packet Forwarding...","description":"\nAn 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).\n\nWhen 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.\n\nPlease 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.\n\nThe following log message can be seen when the issue occurs:\n\nCmerror Op Set: Host Loopback: HOST LOOPBACK WEDGE DETECTED IN PATH ID \u003cid\u003e (URI: /fpc/\u003cfpc\u003e/pfe/\u003cpfe\u003e/cm/\u003ccm\u003e/Host_Loopback/\u003ccm\u003e/HOST_LOOPBACK_MAKE_CMERROR_ID[\u003cid\u003e])\nThis issue affects Juniper Networks Junos OS:\n\n\n\n  *  All versions earlier than 20.4R3-S8;\n  *  21.1 versions earlier than 21.1R3-S4;\n  *  21.2 versions earlier than 21.2R3-S6;\n  *  21.3 versions earlier than 21.3R3-S3;\n  *  21.4 versions earlier than 21.4R3-S5;\n  *  22.1 versions earlier than 22.1R2-S2, 22.1R3;\n  *  22.2 versions earlier than 22.2R2-S1, 22.2R3.\n\n\n\n\n\n\n","status":"published","published":"2024-01-12T03:30:48Z","modified":"2024-01-12T03:30:55Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"medium"}],"cwes":["CWE-76"],"updated_at":"2026-11-02T14:55:23.490471Z"}],"nvd":[{"id":"CVE-2024-21600","description":"\nAn 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).\n\nWhen 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.\n\nPlease 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.\n\nThe following log message can be seen when the issue occurs:\n\nCmerror Op Set: Host Loopback: HOST LOOPBACK WEDGE DETECTED IN PATH ID \u003cid\u003e (URI: /fpc/\u003cfpc\u003e/pfe/\u003cpfe\u003e/cm/\u003ccm\u003e/Host_Loopback/\u003ccm\u003e/HOST_LOOPBACK_MAKE_CMERROR_ID[\u003cid\u003e])\nThis issue affects Juniper Networks Junos OS:\n\n\n\n  *  All versions earlier than 20.4R3-S8;\n  *  21.1 versions earlier than 21.1R3-S4;\n  *  21.2 versions earlier than 21.2R3-S6;\n  *  21.3 versions earlier than 21.3R3-S3;\n  *  21.4 versions earlier than 21.4R3-S5;\n  *  22.1 versions earlier than 22.1R2-S2, 22.1R3;\n  *  22.2 versions earlier than 22.2R2-S1, 22.2R3.\n\n\n\n\n\n\n","status":"published","published":"2024-01-12T01:15:47.857Z","modified":"2026-06-17T07:09:48.25Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"secondary"},{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"primary"}],"cwes":["CWE-76"],"updated_at":"2026-11-02T14:09:30.070039Z"}]}}