CVE-2024-21591

Public Exploit
Junos OS: SRX Series and EX Series: Security Vulnerability in J-web allows a preAuth Remote Code Execution

Description

An Out-of-bounds Write vulnerability in J-Web of Juniper Networks Junos OS on SRX Series and EX Series allows an unauthenticated, network-based attacker to cause a Denial of Service (DoS), or Remote Code Execution (RCE) and obtain root privileges on the device. This issue is caused by use of an insecure function allowing an attacker to overwrite arbitrary memory. This issue affects Juniper Networks Junos OS SRX Series and EX Series: * Junos OS versions earlier than 20.4R3-S9; * Junos OS 21.2 versions earlier than 21.2R3-S7; * Junos OS 21.3 versions earlier than 21.3R3-S5; * Junos OS 21.4 versions earlier than 21.4R3-S5; * Junos OS 22.1 versions earlier than 22.1R3-S4; * Junos OS 22.2 versions earlier than 22.2R3-S3; * Junos OS 22.3 versions earlier than 22.3R3-S2; * Junos OS 22.4 versions earlier than 22.4R2-S2, 22.4R3.

Remediation

Solution:

  • The following software releases have been updated to resolve this specific issue: Junos OS: 20.4R3-S9, 21.2R3-S7, 21.3R3-S5, 21.4R3-S5, 22.1R3-S4, 22.2R3-S3, 22.3R3-S2, 22.4R2-S2, 22.4R3, 23.2R1-S1, 23.2R2, 23.4R1, and all subsequent releases.

Workaround:

  • Disable J-Web, or limit access to only trusted hosts.

Category

9.8
CVSS
Severity: Critical
CVSS 3.1 •
EPSS 23.48% Top 5%
Vendor Advisory juniper.net
Affected: Juniper Networks Junos OS
Published at:
Updated at:

References

Link Tags
https://supportportal.juniper.net/JSA75729 vendor advisory
https://www.first.org/cvss/calculator/4.0#CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N third party advisory technical description
https://curesec.com/blog/article/CVE-2024-21591_Juniper_Remote_Code_Exec.html third party advisory exploit

Frequently Asked Questions

What is the severity of CVE-2024-21591?
CVE-2024-21591 has been scored as a critical severity vulnerability.
How to fix CVE-2024-21591?
To fix CVE-2024-21591: The following software releases have been updated to resolve this specific issue: Junos OS: 20.4R3-S9, 21.2R3-S7, 21.3R3-S5, 21.4R3-S5, 22.1R3-S4, 22.2R3-S3, 22.3R3-S2, 22.4R2-S2, 22.4R3, 23.2R1-S1, 23.2R2, 23.4R1, and all subsequent releases.
Is CVE-2024-21591 being actively exploited in the wild?
It is possible that CVE-2024-21591 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~23% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2024-21591?
CVE-2024-21591 affects Juniper Networks Junos OS.
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