CVE-2024-21587

<br /> An Improper Handling of Exceptional Conditions vulnerability in the broadband edge subscriber management daemon (bbe-smgd) of Juniper Networks Junos OS on MX Series allows an attacker directly connected to the vulnerable system who repeatedly flaps DHCP subscriber sessions to cause a slow memory leak, ultimately leading to a Denial of Service (DoS). Memory can only be recovered by manually restarting bbe-smgd.<br /> <br /> This issue only occurs if BFD liveness detection for DHCP subscribers is enabled. Systems without BFD liveness detection enabled are not vulnerable to this issue.<br /> <br /> Indication of the issue can be observed by periodically executing the &amp;#39;show system processes extensive&amp;#39; command, which will indicate an increase in memory allocation for bbe-smgd. A small amount of memory is leaked every time a DHCP subscriber logs in, which will become visible over time, ultimately leading to memory starvation.<br /> <br /> user@junos&gt; show system processes extensive | match bbe-smgd<br /> 13071 root 24 0 415M 201M select 0 0:41 7.28% bbe-smgd{bbe-smgd}<br /> 13071 root 20 0 415M 201M select 1 0:04 0.00% bbe-smgd{bbe-smgd}<br /> ...<br /> user@junos&gt; show system processes extensive | match bbe-smgd<br /> 13071 root 20 0 420M 208M select 0 4:33 0.10% bbe-smgd{bbe-smgd}<br /> 13071 root 20 0 420M 208M select 0 0:12 0.00% bbe-smgd{bbe-smgd}<br /> ...<br /> This issue affects Juniper Networks Junos OS on MX Series:<br /> <br /> <br /> <br /> * All versions earlier than 20.4R3-S9;<br /> * 21.2 versions earlier than 21.2R3-S7;<br /> * 21.3 versions earlier than 21.3R3-S5;<br /> * 21.4 versions earlier than 21.4R3-S5;<br /> * 22.1 versions earlier than 22.1R3-S4;<br /> * 22.2 versions earlier than 22.2R3-S3;<br /> * 22.3 versions earlier than 22.3R3-S2;<br /> * 22.4 versions earlier than 22.4R2-S2, 22.4R3;<br /> * 23.2 versions earlier than 23.2R1-S1, 23.2R2.<br /> <br /> <br /> <br /> <br /> <br /> <br />