Junos OS: Due to a race condition AgentD process causes a memory corruption and FPC reset

published 2024-10-11 2 y ago modified 2026-06-17 4 mo ago also EUVD-2024-42498

cvss: 5.9; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 30%
public exploits: 0; none known

A Time-of-check Time-of-use (TOCTOU) Race Condition vulnerability in the AgentD process of Juniper Networks Junos OS allows an attacker who is already causing impact to established sessions which generates counter changes picked up by the AgentD process during telemetry polling, to move the AgentD process into a state where AgentD attempts to reap an already destroyed sensor. This reaping attempt then leads to memory corruption causing the FPC to crash which is a Denial of Service (DoS).

The FPC will recover automatically without user intervention after the crash. This issue affects Junos OS:

* All versions before 21.4R3-S9 * From 22.2 before 22.2R3-S5, * From 22.3 before 22.3R3-S4, * From 22.4 before 22.4R3-S3, * From 23.2 before 23.2R2-S2, * From 23.4 before 23.4R2.

This issue does not affect Junos OS Evolved.

Patch / fix

fixed in 1

Juniper Networks Junos OS 21.4R3-S9, 22.2R3-S5, 22.3R3-S4, 22.4R3-S3, 23.2R2-S2, 23.4R2

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 2 y ago (2024-10-11)

Exploit prediction

0.36% chance of exploitation in the next 30 days, higher than 30% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	5.9	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA	4.0	8.2	CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/AU:Y/R:A/RE:L/U:Green
CNA	4.0	8.2	CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:Y/R:A/V:X/RE:L/U:Green

Affected products

Juniper Networks Junos OS

Classification

Weakness

CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition

References

supportportal.juniper.net /JSA88121
vendor-advisory

Sources

CVE List CVE-2024-47494
NVD CVE-2024-47494

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary