This advisory is for organizations that use Juniper SRX Series Firewalls and Juniper EX Series switches. If your organization does not use these products, this notification may be discarded.
Summary
Juniper has released security updates to address critical vulnerabilities noted in J-Web in Juno OS for SRX firewalls and EX switches. This vulnerability would allow an unauthenticated network-based attacker to overwrite arbitrary memory locations on the affected device to execute a Denial of Service (DoS) or Remote Code Execution (RCE) attack which could result in root access on the device(s).
CVE-2024-21591 – Out of bounds write vulnerability Juno OS SRX and EX Series
CSVVv3.1: 9.8
An Out-of-bounds Write vulnerability in J-Web of Juniper Networks Junos OS 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.
Affected Platforms
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
Mitigations
A patch has been released.
Alternatively, disable the J-Web interface and/or restrict J-Web access to only trusted network hosts.
Additional Resources
https://supportportal.juniper.net/s/article/2024-01-Security-Bulletin-Junos-OS-SRX-Series-and-EX-Series-Security-Vulnerability-in-J-web-allows-a-preAuth-Remote-Code-Execution-CVE-2024-21591?language=en_US
https://www.bleepingcomputer.com/news/security/juniper-warns-of-critical-rce-bug-in-its-firewalls-and-switches/
https://nvd.nist.gov/vuln/detail/CVE-2024-21591
