cbcvebase.
CVE-2023-36847
published 2023-08-17

CVE-2023-36847: A Missing Authentication for Critical Function vulnerability in Juniper Networks Junos OS on EX Series allows an unauthenticated, network-based attacker to…

PriorityP188medium5.3CVSS 3.1
AVNACLPRNUINSUCNILAN
KEVITWEXPLOITRansomwareInitial access
CISA Known Exploited Vulnerabilitydue 2023-11-17
Exploited in the wild
EPSS
84.69%
99.7th percentile
A Missing Authentication for Critical Function vulnerability in Juniper Networks Junos OS on EX Series allows an unauthenticated, network-based attacker to cause limited impact to the file system integrity. With a specific request to installAppPackage.php that doesn't require authentication an attacker is able to upload arbitrary files via J-Web, leading to a loss of integrity for a certain part of the file system, which may allow chaining to other vulnerabilities. This issue affects Juniper Networks Junos OS on EX Series: * All versions prior to 20.4R3-S8; * 21.1 versions 21.1R1 and later; * 21.2 versions prior to 21.2R3-S6; * 21.3 versions prior to 21.3R3-S5; * 21.4 versions prior to 21.4R3-S4; * 22.1 versions prior to 22.1R3-S3; * 22.2 versions prior to 22.2R3-S1; * 22.3 versions prior to 22.3R2-S2, 22.3R3; * 22.4 versions prior to 22.4R2-S1, 22.4R3.

Affected

22 ranges
VendorProductVersion rangeFixed in
juniperex_series
juniperj-web
juniperjunos< 20.420.4
juniperjunos
juniperjunos
juniperjunos
juniperjunos
juniperjunos
juniperjunos
juniperjunos
juniperjunos
juniperjunos
juniperjunos_os
juniper_networksjunos_os< 20.4R3-S820.4R3-S8
juniper_networksjunos_os>= 21.1 < 21.1*21.1*
juniper_networksjunos_os>= 21.2 < 21.2R3-S621.2R3-S6
juniper_networksjunos_os>= 21.3 < 21.3R3-S521.3R3-S5
juniper_networksjunos_os>= 21.4 < 21.4R3-S421.4R3-S4
juniper_networksjunos_os>= 22.1 < 22.1R3-S322.1R3-S3
juniper_networksjunos_os>= 22.2 < 22.2R3-S122.2R3-S1
juniper_networksjunos_os>= 22.3 < 22.3R2-S2, 22.3R322.3R2-S2, 22.3R3
juniper_networksjunos_os>= 22.4 < 22.4R2-S1, 22.4R322.4R2-S1, 22.4R3

Detection & IOCsextracted from sources · hover to see the quote

path/installAppPackage.php
path/webauth_operation.php
path/var/tmp/
commandrs=do_upload&rsargs[]=[{"fileData": "data:text/html;base64,...", "fileName": "<rand>.php", "csize": ...}]
commandGET /webauth_operation.php?PHPRC=/var/tmp/<inifile>
  • Monitor for unauthenticated POST requests to /webauth_operation.php with 'rs=do_upload' parameter, which indicates exploitation of the file upload chain (CVE-2023-36846/36847).
  • Detect GET requests to /webauth_operation.php with a PHPRC query parameter pointing to /var/tmp/, indicating PHPRC environment variable manipulation for RCE.
  • Monitor for unauthenticated POST requests to /installAppPackage.php, the specific endpoint targeted by CVE-2023-36847 for arbitrary file upload.
  • Use Shodan query 'title:"Juniper Web Device Manager"' to identify internet-exposed J-Web interfaces that may be vulnerable.
  • Look for .php and .ini file uploads to /var/tmp/ via J-Web as part of the two-file exploit chain (watchTowr PoC), where the .ini file sets auto_prepend_file.
  • ShadowServer and GreyNoise have observed active probing of Junos OS endpoints; correlate inbound J-Web traffic against threat intel feeds from these sources.
  • ·CVE-2023-36847 alone causes limited file system integrity impact; critical RCE is only achieved when chained with CVE-2023-36844/36845/36846. Detection should account for the full chain.
  • ·VulnCheck demonstrated a single-CVE (CVE-2023-36845) RCE path using only environment variable manipulation and the data:// protocol, bypassing the need to upload files — meaning file-upload-based detections alone are insufficient.
  • ·Older Juniper SRX devices (e.g., SRX210) may lack the do_fileUpload() function, meaning the watchTowr two-file exploit chain may not work on them, but the single-curl VulnCheck exploit may still apply.

CVSS provenance

nvdv3.15.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
vulncheck5.3MEDIUM
cisa5.3MEDIUM
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