CVE-2024-21619: Junos OS: SRX Series and EX Series: J-Web - unauthenticated access to temporary files containing sensitive information

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.9% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-01-25 · updated 2026-06-17
Weakness: CWE-209

Description

A Missing Authentication for Critical Function vulnerability combined with a Generation of Error Message Containing Sensitive Information vulnerability in J-Web of Juniper Networks Junos OS on SRX Series and EX Series allows an unauthenticated, network-based attacker to access sensitive system information. When a user logs in, a temporary file which contains the configuration of the device (as visible to that user) is created in the /cache folder. An unauthenticated attacker can then attempt to access such a file by sending a specific request to the device trying to guess the name of such a file. Successful exploitation will reveal configuration information. This issue affects Juniper Networks Junos OS on SRX Series and EX Series: * 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-S6; * 22.1 versions earlier than 22.1R3-S5; * 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.

Affected products

Juniper Junos OS: before 20.4; 20.4, 20.4-r1, 20.4-r1-s1, 20.4-r2, 20.4-r2-s1, 20.4-r2-s2 (+89) — fixed in 20.4

How to fix

Upgrade to a fixed version: Juniper Junos OS 20.4. Check the vendor advisory for mitigations.

References

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