Threats / Juniper / CVE-2023-36845
CVE-2023-36845
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-09-19
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 · 2023-11-135EPSS 0.9507 (verify live)6Exploit Weaponized · public PoC7CVSS 9.83CISA SSVC Exploitation: active · Automatable: yes · Impact: total4
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
90 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 0.9507 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
CVSS 9.8 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H) · Affected: Juniper, Junos OS. Confirm exact fixed builds in the vendor advisory.CVSS — CNA-assigned (CVE.org), version 3.1, set at disclosure.
Weakness (CWE)
Mapped to CWE-473 CWE-473.CWE — CNA-assigned (CVE.org); the weakness class drives how the flaw is exploited.
CISA SSVC (triage disposition)
Exploitation: active · Automatable: yes · Technical Impact: totalCISA's own stakeholder-specific triage inputs, published in the CVE record (CISA Coordinator role). NOTE: this is CISA's three decision points; the final Act/Attend/Track decision also requires a Mission & Well-being input not published here, so no overall decision is asserted.
Currency of the record
CISA added this to its KEV catalog 88 days after the CVE record was published.KEV lag = CISA-KEV dateAdded − CVE.org datePublished; a floor on how long the known-exploited flaw sat in the public record before the federal catalog listed it. Severity/weakness here is CNA- or CISA-assigned (current at disclosure), independent of NVD's analysis backlog.
Public exploit available
Public exploit tooling is catalogued for this CVE (a functional/weaponized public exploit). Catalog entries: Metasploit module, nuclei template. We link the catalog page(s) only — no payload or code is hosted or restated here.Link, never host — the catalog page is the source; basicsecurity.net does not redistribute payloads.
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 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’tEstablished (cited)
Coverage gaps — stated, not hidden
Disclosure & credit2
Catalogued by juniperCNA
Credited with finding itLYS, working with DEVCORE Internship Programfinder
Found an error? Propose a correction.
A correction is a cited counter-claim — it must cite a source,
gets reviewed by a second human, and is never auto-applied. See the
correction convention and our identity
npub1j7gt9ky7sfcrjn8jjee6693dkzvk4rahs0fk2suu7968dfns62zs3mqm3y.