Threats / Juniper / CVE-2023-36847
CVE-2023-36847
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-06-22
Juniper Junos OS vulnerability
Juniper Junos OS on EX Series lacks authentication for the installAppPackage.php function, allowing unauthenticated attackers to upload arbitrary files via J-Web and compromise file system integrity.
Verdict
Today item — known-exploited.
An unauthenticated network attacker can upload arbitrary files to affected EX Series devices through an unprotected J-Web endpoint, degrading file system integrity and potentially enabling further exploitation chains.
01
Is it exploitable?
— the evidence, ranked above the scoreExploit available
Fully weaponized — public exploit code is cataloged for this vulnerability.We link the existence of the exploit; we do not host or redistribute payloads.
Reported exploitation
8 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2023-11-13).
Probability (EPSS)
EPSS 0.84692 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Juniper, Junos OS. Confirm exact fixed builds in the vendor advisory.
Weakness (CWE)
Mapped to CWE-306 Missing Authentication — weakness family: Authentication.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution not established
No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.
03
Why it matters
— the attack path, told twice: adversary, then board1
Front door — unauthenticated access narrative 1
Attacker
I identify the unprotected installAppPackage.php endpoint accessible without credentials on the J-Web interface.
Business
The organization's network device exposes a critical administrative function to any network-connected party.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I craft and send a request to upload a malicious file to the device file system without providing authentication.
Business
Arbitrary file placement compromises the integrity and trustworthiness of the device's operating environment.
3
Lateral reach — past segmentation narrative 3
Attacker
I leverage the uploaded file as a pivot point to chain additional exploits or establish persistence on the device.
Business
The initial file upload vulnerability becomes a staging ground for deeper compromise of network infrastructure.
04
What to do
— defensible action- Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05
Coverage & confidence
— what we know, and what we don’tEstablished (cited)
Coverage gaps — stated, not hidden
Disclosure & credit2
Catalogued by juniperCNA
Credited with finding itLYS, working with DEVCORE Internship Programfinder