CVE-2024-21587 : Vulnerability Insights and Analysis

This CVE-2024-21587 article provides detailed information about a vulnerability in Juniper Networks Junos OS on MX Series that could result in a memory leak in the bbe-smgd process if BFD liveness detection for DHCP subscribers is enabled.

Understanding CVE-2024-21587

This section delves into the specifics of CVE-2024-21587, highlighting the vulnerability's description, impact, affected systems, exploitation mechanism, mitigation, and prevention strategies.

What is CVE-2024-21587?

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 attackers to cause a slow memory leak by repeatedly flapping DHCP subscriber sessions. This can lead to a Denial of Service (DoS) condition. Memory recovery necessitates manual restart of bbe-smgd, specifically impacting systems with BFD liveness detection enabled for DHCP subscribers.

The Impact of CVE-2024-21587

The vulnerability may result in a memory leak in the bbe-smgd process, leading to a DoS scenario. Systems with BFD liveness detection for DHCP subscribers enabled are susceptible to this issue, manifesting through memory starvation over time as DHCP subscribers log in, indicating increased memory allocation for bbe-smgd.

Technical Details of CVE-2024-21587

Explore the vulnerability's technical intricacies, including the vulnerability description, affected systems and versions, and exploitation mechanism.

Vulnerability Description

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 attackers to trigger a memory leak by manipulating DHCP subscriber sessions, leading to a DoS condition.

Affected Systems and Versions

Juniper Networks Junos OS on MX Series versions earlier than 20.4R3-S9, 21.2R3-S7, 21.3R3-S5, 21.4R3-S5, 22.1R3-S4, 22.2R3-S3, 22.3R3-S2, 22.4R2-S2, 22.4R3, 23.2R1-S1, and 23.2R2 are affected by this vulnerability.

Exploitation Mechanism

The vulnerability can be exploited by directly connecting to the vulnerable system and causing frequent flapping of DHCP subscriber sessions, resulting in a slow memory leak that can trigger a DoS condition.

Mitigation and Prevention

Learn about the necessary steps to mitigate the impact of CVE-2024-21587, including immediate actions, long-term security practices, and the importance of patching and updates.

Immediate Steps to Take

Mitigate the vulnerability by disabling BFD liveness detection for DHCP subscribers and periodically restarting the bbe-smgd process to restore service.

Long-Term Security Practices

Incorporate regular security updates, network monitoring, and access control measures to enhance overall system security and reduce the risk of similar vulnerabilities.

Patching and Updates

Refer to Juniper's advisory JSA75725 for updated software releases that address and resolve the CVE-2024-21587 vulnerability across affected versions of Junos OS on MX Series.