CISA KEV · Known exploitedMedium

CVE-2023-36844

Juniper Junos OS

A PHP External Variable Modification vulnerability in J-Web of Juniper Networks Junos OS on EX Series allows an unauthenticated, network-based attacker to control certain, important environment variables. Using a crafted request an attacker is able to modify certain PHP environment variables leading to partial loss of integrity, which may allow chaining to other vulnerabilities. This issue affects Juniper Networks Junos OS on EX Series: * All versions prior to 20.4R3-S9; * 21.1 versions 21.1R1 and later; * 21.2 versions prior to 21.2R3-S7; * 21.3 versions prior to 21.3R3-S5; * 21.4 versions...

CVSS: 5.3
EPSS: 91.4%
CISA KEV: Listed
Published: 2023.08.18

PRIORITY ASSESSMENT

Immediate review

CISA has listed this vulnerability in the Known Exploited Vulnerabilities catalog.

Known exploitationConfirmed by CISA KEV

Exploit probability91.4%

Technical severityCVSS 5.3

Vulnerability overview

Affected product and versions

Product: Juniper Junos OS
Affected versions: 21.1, 21.2, 21.3, 21.4, 22.1, 22.2, 22.3, 22.4, 23.2, < 20.4, 20.4
Fixed versions: 20.4

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

CISA required action

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Due date: 2023.11.17

1
Identify
Confirm that Juniper Junos OS and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
CWE: CWE-473
KEV added: 2023.11.13
Ransomware use: 미확인