title: 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.
problem types: CWE-787 Out-of-bounds Write
affected:
{
defaultStatus: unaffected
platforms: [SRX Series, EX Series]
product: Junos OS
vendor: Juniper Networks
versions:
lessThan: 20.4R3-S9, status: affected, version: 0, versionType: semver
lessThan: 21.2R3-S7, status: affected, version: 21.2, versionType: semver
lessThan: 21.3R3-S5, status: affected, version: 21.3, versionType: semver
lessThan: 21.4R3-S5, status: affected, version: 21.4, versionType: semver
lessThan: 22.1R3-S4, status: affected, version: 22.1, versionType: semver
lessThan: 22.2R3-S3, status: affected, version: 22.2, versionType: semver
lessThan: 22.3R3-S2, status: affected, version: 22.3, versionType: semver
lessThan: 22.4R2-S2, 22.4R3, status: affected, version: 22.4, versionType: semver
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: HIGH
baseScore: 9.8
baseSeverity: CRITICAL
confidentialityImpact: HIGH
integrityImpact: HIGH
privilegesRequired: NONE
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
version: 3.1
]
format: CVSS
scenarios: GENERAL
exploits: Juniper SIRT is not aware of any malicious exploitation of this vulnerability.
solutions: 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.
workarounds: Disable J-Web, or limit access to only trusted hosts.