{"cve":"CVE-2023-36849","nvd":{"published":"2023-07-14T18:15:10.503","modified":"2026-06-17T06:07:13.617","status":"Modified","description":"An Improper Check or Handling of Exceptional Conditions vulnerability in the Layer-2 control protocols daemon (l2cpd) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated adjacent attacker to cause a Denial of Service (DoS).\n\nWhen a malformed LLDP packet is received, l2cpd will crash and restart. The impact of the l2cpd crash is reinitialization of STP protocols (RSTP, MSTP or VSTP), and MVRP and ERP. Also, if any services depend on LLDP state (like PoE or VoIP device recognition), then these will also be affected. Continued receipt of such packets will lead to a sustained Denial of Service.\n\nThis issue affects:\nJuniper Networks Junos OS\n21.4 versions prior to 21.4R3-S3;\n22.1 versions prior to 22.1R3-S3;\n22.2 versions prior to 22.2R2-S1, 22.2R3;\n22.3 versions prior to 22.3R2.\n\nJuniper Networks Junos OS Evolved\n21.4-EVO versions prior to 21.4R3-S2-EVO;\n22.1-EVO versions prior to 22.1R3-S3-EVO;\n22.2-EVO versions prior to 22.2R2-S1-EVO, 22.2R3-EVO;\n22.3-EVO versions prior to 22.3R2-EVO.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":6.5},"cwes":["CWE-703"],"references":["https://supportportal.juniper.net/JSA71660","https://supportportal.juniper.net/JSA71660"],"products":["juniper:junos","juniper:junos_os_evolved"],"source":"nvd","synced_at":"2026-10-19T21:38:35.729974749+00:00"},"epss":{"cve":"CVE-2023-36849","score":0.00303,"percentile":0.23119,"date":"2026-11-01"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}