Description

An Improper Handling of Exceptional Conditions vulnerability in the Class of Service daemon (cosd) of Juniper Networks Junos OS allows an authenticated, network-based attacker with low privileges to cause a limited Denial of Service (DoS).

In a scaled CoS scenario with 1000s of interfaces, when specific low privileged commands, received over NETCONF, SSH or telnet, are handled by cosd on behalf of mgd, the respective child management daemon (mgd) processes will get stuck. In case of (Netconf over) SSH this leads to stuck SSH sessions, so that when the connection-limit for SSH is reached, new sessions can't be established anymore. A similar behavior will be seen for telnet etc.

Stuck mgd processes can be monitored by executing the following command:

  user@host> show system processes extensive | match mgd | match sbwait

This issue affects Juniper Networks Junos OS:
* All versions earlier than 20.4R3-S9;
* 21.2 versions earlier than 21.2R3-S7;
* 21.3 versions earlier than 21.3R3-S5;
* 21.4 versions earlier than 21.4R3-S5;
* 22.1 versions earlier than 22.1R3-S4;
* 22.2 versions earlier than 22.2R3-S3;
* 22.3 versions earlier than 22.3R3-S2;
* 22.4 versions earlier than 22.4R3;
* 23.2 versions earlier than 23.2R1-S2, 23.2R2.

Classification

CVE ID: CVE-2024-21610

CVSS Base Severity: MEDIUM

CVSS Base Score: 4.3

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

Affected Products

Vendor: Juniper Networks

Product: Junos OS

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.1% (probability of being exploited)

EPSS Percentile: 28.44% (scored less or equal to compared to others)

EPSS Date: 2025-06-17 (when was this score calculated)

Stakeholder-Specific Vulnerability Categorization (SSVC)

SSVC Exploitation: none

SSVC Technical Impact: partial

SSVC Automatable: false

References

https://nvd.nist.gov/vuln/detail/CVE-2024-21610
http://supportportal.juniper.net/JSA75751

Timeline