Threats / Juniper / CVE-2023-36844
CVE-2023-36844
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-06-22
Juniper Junos OS vulnerability
Juniper Junos OS on EX Series contains a PHP external variable modification vulnerability allowing unauthenticated network attackers to control environment variables, potentially enabling further exploitation.
Verdict
Today item — known-exploited.
An unauthenticated remote attacker can modify PHP environment variables on affected Junos OS EX Series devices through crafted requests. This integrity compromise may facilitate chaining to additional vulnerabilities for greater impact.
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
470 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 0.89628 — 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-473 CWE-473.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
WeaknessCWE-473 · CWE-473
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 craft a network request targeting PHP environment variable handling on the EX Series device without requiring authentication.
Business
The device's configuration integrity is compromised, creating an entry point for secondary attacks that could disrupt network operations.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I modify critical PHP environment variables to alter application behavior or bypass security controls on the affected system.
Business
Attackers gain a foothold to chain this vulnerability with others, potentially leading to unauthorized access or system compromise.
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