CVE-2023-36849
MediumCVSS 6.5Exploitation Probability (EPSS)
Low risk18th percentile - higher than 18% of all known CVEs
Summary
CVE-2023-36849 describes an improper check or handling of exceptional conditions vulnerability in the Layer-2 control protocols daemon (l2cpd) of Juniper Networks Junos OS. This allows an unauthenticated adjacent attacker to cause a Denial of Service (DoS) by sending malformed LLDP packets.
Risk Assessment
An attacker can lead to a sustained l2cpd crash, resulting in reinitialization of STP protocols and affecting services dependent on LLDP state, such as PoE or VoIP device recognition. This can cause significant disruptions in network operations.
Recommendation
It is recommended to update Junos OS to versions that are not vulnerable to this issue to minimize the risk of DoS attacks. Additionally, monitoring network traffic for suspicious LLDP packets is advised.
Original NVD description (English source)
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). When 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. This issue affects: Juniper Networks Junos OS 21.4 versions prior to 21.4R3-S3; 22.1 versions prior to 22.1R3-S3; 22.2 versions prior to 22.2R2-S1, 22.2R3; 22.3 versions prior to 22.3R2. Juniper Networks Junos OS Evolved 21.4-EVO versions prior to 21.4R3-S2-EVO; 22.1-EVO versions prior to 22.1R3-S3-EVO; 22.2-EVO versions prior to 22.2R2-S1-EVO, 22.2R3-EVO; 22.3-EVO versions prior to 22.3R2-EVO.