CVE-2023-44188

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.

Weakness

The product checks the state of a resource before using that resource, but the resource’s state can change between the check and the use in a way that invalidates the results of the check. This can cause the product to perform invalid actions when the resource is in an unexpected state.

Affected Software

Potential Mitigations

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/27.html
• https://cwe.mitre.org/data/definitions/29.html

References

• https://supportportal.juniper.net/JSA73152