CVE-2023-36844Known exploitationPublic exploitNetwork attack vector

Integrity loss via attacker-controlled PHP environment variables

Published Aug 17, 2023 · Updated Oct 21, 2025

PHP external variable modification in J-Web for Juniper Networks Junos OS on EX Series allows remote attackers to alter PHP variables. A crafted unauthenticated HTTP request overwrites PHPRC, causing PHP to load an attacker-selected configuration file and changing process configuration. J-Web must be enabled through HTTP or HTTPS management, and code execution requires chaining with separate file-upload flaws.

CVSS severity5.3
Medium
EPSS probability89.96%
Next 30 days · Sep 20, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

PHP external variable modification in J-Web for Juniper Networks Junos OS on EX Series allows remote attackers to alter PHP variables. A crafted unauthenticated HTTP request overwrites PHPRC, causing PHP to load an attacker-selected configuration file and changing process configuration. J-Web must be enabled through HTTP or HTTPS management, and code execution requires chaining with separate file-upload flaws.

The record

CVE
CVE-2023-36844
Published
Aug 17, 2023
Updated
Oct 21, 2025
Vendor
Juniper Networks
Product
Junos OS
Classifications
CWE-473, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 17, 2023CVE publishedPublication date reported by the CVE source.
  2. Oct 21, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <20.4R3-S9
  2. Affected versionversion=21.1 <21.1*
  3. Affected versionversion=21.2 <21.2R3-S6
  4. Affected versionversion=21.3 <21.3R3-S5
  5. Affected versionversion=21.4 <21.4R3-S5
  6. Affected versionversion=22.1 <22.1R3-S4
  7. Affected versionversion=22.2 <22.2R3-S2
  8. Affected versionversion=22.3 <22.3R3-S1
  9. Affected versionversion=22.4 <22.4R2-S2, 22.4R3
  10. Affected versionversion=23.2 <23.2R1-S1, 23.2R2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Juniper Networks · Junos OSversion=0 <20.4R3-S9; version=21.1 <21.1*; version=21.2 <21.2R3-S6; version=21.3 <21.3R3-S5; version=21.4 <21.4R3-S5; version=22.1 <22.1R3-S4; version=22.2 <22.2R3-S2; version=22.3 <22.3R3-S1; version=22.4 <22.4R2-S2, 22.4R3; version=23.2 <23.2R1-S1, 23.2R2

Published CVSS scores

5.3Juniper NetworksCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsShadowserver observations through Sep 20, 2026. Gaps indicate unavailable data.
Sep 14, 2026Sep 20, 2026
View daily counts
Reporting dayUnique IPs
Sep 14, 2026Unavailable
Sep 15, 2026Unavailable
Sep 16, 2026Unavailable
Sep 17, 20261
Sep 18, 2026Unavailable
Sep 19, 2026Unavailable
Sep 20, 2026Unavailable
Latest reporting daySep 20, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationReported
Public exploitPublished

Weakness, pattern, technique

CWE-473PHP External Variable Modification
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Reported exploitation

Technologies

Your stack

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Your stack

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