A Time-of-check Time-of-use (TOCTOU) Race Condition vulnerability in telemetry processing of Juniper Networks Junos OS allows a network-based authenticated attacker to flood the system with multiple telemetry requests, causing the Junos Kernel Debugging Streaming Daemon (jkdsd) process to crash, leading to a Denial of Service (DoS). Continued receipt and processing of telemetry requests will repeatedly crash the jkdsd process and sustain the Denial of Service (DoS) condition.
 

This issue is seen on all Junos platforms. The crash is triggered when multiple telemetry requests come from different collectors. As the load increases, the Dynamic Rendering Daemon (drend) decides to defer processing and continue later, which results in a timing issue accessing stale memory, causing the jkdsd process to crash and restart.

Note: jkdsd is not shipped with SRX Series devices and therefore are not affected by this vulnerability.

This issue affects:

Juniper Networks Junos OS:

• 20.4 versions prior to 20.4R3-S9;
• 21.1 versions 21.1R1 and later;
• 21.2 versions prior to 21.2R3-S6;
• 21.3 versions prior to 21.3R3-S5;
• 21.4 versions prior to 21.4R3-S5;
• 22.1 versions prior to 22.1R3-S4;
• 22.2 versions prior to 22.2R3-S2;
• 22.3 versions prior to 22.3R2-S1, 22.3R3-S1;
• 22.4 versions prior to 22.4R2-S2, 22.4R3;
• 23.1 versions prior to 23.1R2.

This issue does not affect Juniper Networks Junos OS versions prior to 19.4R1.

Juniper SIRT is not aware of any malicious exploitation of this vulnerability.

This issue was seen during production usage.

This issue has been assigned CVE-2023-44188.

The following software releases have been updated to resolve this specific issue: Junos OS 20.4R3-S9, 21.2R3-S6, 21.4R3-S5, 22.1R3-S4, 22.2R3-S2, 22.3R2-S1, 22.3R2-S2, 22.3R3-S1, 22.4R2-S2, 22.4R3, 23.1R2, 23.2R1, and all subsequent releases.
 

This issue is being tracked as PR 1734718 which is visible on the Customer Support website.

Note: Juniper SIRT's policy [juniper.net] is not to evaluate releases which are beyond End of Engineering (EOE) or End of Life (EOL).

2023-10-11: Initial Publication
2023-10-25: Added note that SRX Series devices are not vulnerable to this issue
2024-02-21: Removed Junos OS 23.2 from affected releases (resolved in R1)

• KB16613: Overview of the Juniper Networks SIRT Quarterly Security Bulletin Publication Process [juniper.net]
• KB16765: In which releases are vulnerabilities fixed? [juniper.net]
• KB16446: Common Vulnerability Scoring System (CVSS) and Juniper's Security Advisories [juniper.net]
• Report a Security Vulnerability - How to Contact the Juniper Networks Security Incident Response Team
• CVE-2023-44188 at cve.mitre.org
• https://supportportal.juniper.net/JSA73152 [juniper.net]