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Threats / Juniper / CVE-2023-36845
CVE-2023-36845 · EUVD no mirror located · GCVE no mirror located Verified 2026-06-22

Juniper Junos OS vulnerability

Juniper Junos OS on EX and SRX Series contains a PHP external variable modification vulnerability allowing unauthenticated attackers to control the PHPRC environment variable and execute arbitrary code.

Verdict

Today item — known-exploited.

An unauthenticated network attacker can craft requests to manipulate PHP execution environment variables, leading to arbitrary code execution on affected Juniper devices. Active exploitation has been observed in the wild.

CISA KEV Yes · 2023-11-133EPSS 0.93546 (verify live)4Exploit Weaponized · public PoC5
01

Is it exploitable?

— the evidence, ranked above the score
Exploit 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
78 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).
CISA KEV ↗Confirmed
Probability (EPSS)
EPSS 0.93546 — 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.
NVD ↗Reported
Weakness (CWE)
Mapped to CWE-473 CWE-473.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
NVD ↗Reported
02

Who’s exploiting it?

— attribution turns risk into urgency
Attribution 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 board
1

Front door — unauthenticated access narrative 1

Attacker
I send a crafted network request that sets the PHPRC environment variable to point to a malicious PHP configuration file.
Business
The organization's network infrastructure becomes a direct attack vector for code execution without requiring authentication.
2

Keys to the kingdom — privilege/identity takeover narrative 2

Attacker
I inject PHP code through the modified execution environment, causing the device to execute my payload during request processing.
Business
Attackers gain arbitrary code execution capability on critical routing and security appliances, compromising network integrity.
3

Lateral reach — past segmentation narrative 3

Attacker
I establish persistent access or pivot to other network segments using the compromised device as a foothold.
Business
The organization faces potential lateral movement, data exfiltration, and loss of control over network perimeter security.
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’t

Established (cited)

  • KEV listing (CISA)
  • EPSS probability (FIRST)
  • Weaponized exploit available (VulnCheck)
  • 78 reported-exploitation source(s)
  • CWE weakness mapping (NVD)
  • Public exploit availability
  • Catalogued by juniper (CNA)
  • Named finder/reporter credit (CVE.org)
  • Coverage gaps — stated, not hidden

  • No EUVD / GCVE mirror in feed — single-authority dependency for the identifier.
  • EPSS & exposure are time-varying; verify live at the source.
  • Threat-actor attribution not established from feed data — absence of a name is not absence of compromise.
  • Disclosure & credit2
    Catalogued by juniperCNA