Threats / Juniper / CVE-2020-1631
CVE-2020-1631
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-08-04
Juniper Junos OS vulnerability
Path traversal vulnerability in Juniper Junos OS HTTP/HTTPS services (J-Web, Web Authentication, Dynamic-VPN, Firewall Authentication, ZTP) enables unauthenticated remote code execution.
Verdict
Today item — known-exploited.
An unauthenticated attacker can exploit path traversal in multiple web-facing services to bypass access controls and achieve remote code execution on affected Juniper devices, with confirmed active exploitation in the wild.
CISA KEV Yes · 2022-03-255EPSS 0.04725 (verify live)6CVSS 8.83CISA SSVC Exploitation: active · Automatable: no · Impact: total4
01
Is it exploitable?
— the evidence, ranked above the scoreReported exploitation
3 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 2022-03-25).
Probability (EPSS)
EPSS 0.04725 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
CVSS 8.8 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/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-22 Path Traversal, CWE-73 CWE-73 — weakness family: Path traversal / file.CWE — CNA-assigned (CVE.org); the weakness class drives how the flaw is exploited.
CISA SSVC (triage disposition)
Exploitation: active · Automatable: no · 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 690 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.
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 malicious HTTP request with path traversal sequences to access restricted files or services without authentication.
Business
Network perimeter security is compromised as unauthenticated access to critical device management interfaces becomes possible.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I leverage the path traversal to reach backend code execution mechanisms exposed through J-Web or authentication services.
Business
Attackers gain arbitrary code execution on network infrastructure, enabling full device compromise and lateral movement.
3
Lateral reach — past segmentation narrative 3
Attacker
I execute commands with device privileges to modify configurations, exfiltrate data, or establish persistence.
Business
Critical network functions are disrupted; confidentiality and integrity of network traffic and configurations are lost.
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