CVE-2023-36851

Junos OS: SRX Series: A vulnerability in J-Web allows an unauthenticated attacker to upload and download arbitrary files

MEDIUM

5.3

CVSS Score

Published: September 26, 2023 at 07:53 PM UTC

Updated: June 17, 2026 at 06:07 AM UTC

91 products affected across 2 vendorsJunosSRX5600SRX5800

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Severity

MEDIUM5.3

Exploitation

CISA KEV

Exploit prediction

EPSS 1%

SSVC

Active

Actively Exploited

CISA Known Exploited Vulnerabilities (KEV) Catalog

EPSS Score1.1%

EPSS (Exploit Prediction Scoring System) estimates a 1.1% chance this CVE is exploited in the wild within the next 30 days — higher than 66% of all CVEs. It complements CVSS: a high EPSS on a mid-severity CVE can still be urgent.

Juniper Junos OS on SRX Series contains a missing authentication for critical function vulnerability that allows an unauthenticated, network-based attacker to cause limited impact to the file system integrity. With a specific request to webauth_operation.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.

Required Action

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

Ransomware Use

Unknown

Added to KEV

Nov 13, 2023

Remediation Due

Nov 17, 2023

1080 days overdue

Notes

https://supportportal.juniper.net/s/article/2023-08-Out-of-Cycle-Security-Bulletin-Junos-OS-SRX-Series-and-EX-Series-Multiple-vulnerabilities-in-J-Web-can-be-combined-to-allow-a-preAuth-Remote-Code-Execution?language=en_US

https://nvd.nist.gov/vuln/detail/CVE-2023-36851

Description

A Missing Authentication for Critical Function vulnerability in Juniper Networks Junos OS on SRX Series allows an unauthenticated, network-based attacker to cause limited impact to the file system integrity. With a specific request to webauth_operation.php that doesn't require authentication, an attacker is able to upload and download arbitrary files via J-Web, leading to a loss of integrity or confidentiality, which may allow chaining to other vulnerabilities. This issue affects Juniper Networks Junos OS on SRX Series: * 21.2 versions prior to 21.2R3-S8; * 21.4 versions prior to 21.4R3-S6; * 22.1 versions prior to 22.1R3-S5; * 22.2 versions prior to 22.2R3-S3; * 22.3 versions prior to 22.3R3-S2; * 22.4 versions prior to 22,4R2-S2, 22.4R3; * 23.2 versions prior to 23.2R1-S2, 23.2R2.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Junos · Juniper Networks

95%

21.2 ≤ v < 21.2R3-S821.4 ≤ v < 21.4R3-S622.1 ≤ v < 22.1R3-S522.2 ≤ v < 22.2R3-S322.3 ≤ v < 22.3R3-S222.4 ≤ v < 22.4R2-S2, 22.4R323.2 ≤ v < 23.2R1-S2, 23.2R221.2 21.2 r1 21.2 r1-s1 21.2 r1-s2 21.2 r2 21.2 r2-s1 21.2 r2-s2 21.2 r3 21.2 r3-s1 21.2 r3-s2 21.2 r3-s3 21.2 r3-s4 21.2 r3-s5 21.2 r3-s6 21.2 r3-s7 21.4 21.4 r1 21.4 r1-s1 21.4 r1-s2 21.4 r2 21.4 r2-s1 21.4 r2-s2 21.4 r3 21.4 r3-s1 21.4 r3-s2 21.4 r3-s3 21.4 r3-s4 21.4 r3-s5 22.1 22.1 r1 22.1 r1-s1 22.1 r1-s2 22.1 r2 22.1 r2-s1 22.1 r2-s2 22.1 r3 22.1 r3-s1 22.1 r3-s2 22.1 r3-s3 22.1 r3-s4 22.2 22.2 r1 22.2 r1-s1 22.2 r1-s2 22.2 r2 22.2 r2-s1 22.2 r2-s2 22.2 r3 22.2 r3-s1 22.2 r3-s2 22.3 22.3 r1 22.3 r1-s1 22.3 r1-s2 22.3 r2 22.3 r2-s1 22.3 r3 22.3 r3-s1 22.4 22.4 r1 22.4 r1-s1 22.4 r1-s2 22.4 r2 22.4 r2-s1 23.2 23.2 r1 23.2 r1-s1

Affected range stops below 21.2R3-S8, so it looks safe — our inference, not a vendor statement

Affected range stops below 21.4R3-S6, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.1R3-S5, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.2R3-S3, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.3R3-S2, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.4R2-S2, 22.4R3, so it looks safe — our inference, not a vendor statement

Affected range stops below 23.2R1-S2, 23.2R2, so it looks safe — our inference, not a vendor statement

juniper-ex2200 (environment) · juniper-ex2200-c (environment) · juniper-ex2200-vc (environment) · juniper-ex2300 (environment) · juniper-ex2300-24mp (environment) · juniper-ex2300-24p (environment) · juniper-ex2300-24t (environment) · juniper-ex2300-48mp (environment) · juniper-ex2300-48p (environment) · juniper-ex2300-48t (environment) · juniper-ex2300-c (environment) · juniper-ex2300m (environment) · juniper-ex3200 (environment) · juniper-ex3300 (environment) · juniper-ex3300-vc (environment) · juniper-ex3400 (environment) · juniper-ex4200 (environment) · juniper-ex4200-vc (environment) · juniper-ex4300 (environment) · juniper-ex4300-24p (environment) · juniper-ex4300-24p-s (environment) · juniper-ex4300-24t (environment) · juniper-ex4300-24t-s (environment) · juniper-ex4300-32f (environment) · juniper-ex4300-32f-dc (environment) · juniper-ex4300-32f-s (environment) · juniper-ex4300-48mp (environment) · juniper-ex4300-48mp-s (environment) · juniper-ex4300-48p (environment) · juniper-ex4300-48p-s (environment) · juniper-ex4300-48t (environment) · juniper-ex4300-48t-afi (environment) · juniper-ex4300-48t-dc (environment) · juniper-ex4300-48t-dc-afi (environment) · juniper-ex4300-48t-s (environment) · juniper-ex4300-48tafi (environment) · juniper-ex4300-48tdc (environment) · juniper-ex4300-48tdc-afi (environment) · juniper-ex4300-mp (environment) · juniper-ex4300-vc (environment) · juniper-ex4300m (environment) · juniper-ex4400 (environment) · juniper-ex4500 (environment) · juniper-ex4500-vc (environment) · juniper-ex4550 (environment) · juniper-ex4550-vc (environment) · juniper-ex4600 (environment) · juniper-ex4600-vc (environment) · juniper-ex4650 (environment) · juniper-ex6200 (environment) · juniper-ex6210 (environment) · juniper-ex8200 (environment) · juniper-ex8200-vc (environment) · juniper-ex8208 (environment) · juniper-ex8216 (environment) · juniper-ex9200 (environment) · juniper-ex9204 (environment) · juniper-ex9208 (environment) · juniper-ex9214 (environment) · juniper-ex9250 (environment) · juniper-ex9251 (environment) · juniper-ex9253 (environment) · juniper-srx100 (environment) · juniper-srx110 (environment) · juniper-srx1400 (environment) · juniper-srx1500 (environment) · juniper-srx210 (environment) · juniper-srx220 (environment) · juniper-srx240 (environment) · juniper-srx240h2 (environment) · juniper-srx240m (environment) · juniper-srx300 (environment) · juniper-srx320 (environment) · juniper-srx340 (environment) · juniper-srx3400 (environment) · juniper-srx345 (environment) · juniper-srx3600 (environment) · juniper-srx380 (environment) · juniper-srx4000 (environment) · juniper-srx4100 (environment) · juniper-srx4200 (environment) · juniper-srx4600 (environment) · juniper-srx5000 (environment) · juniper-srx5400 (environment) · juniper-srx550 (environment) · juniper-srx550-hm (environment) · juniper-srx550m (environment) · juniper-srx5600 (environment) · juniper-srx5800 (environment) · juniper-srx650 (environment)

Ex2200 · Juniperdevice

80%

All versions

Ex2200-C · Juniperdevice

80%

All versions

Ex2200-Vc · Juniperdevice

80%

All versions

Ex2300 · Juniperdevice

80%

All versions