Threats / ASUS / CVE-2023-39780
CVE-2023-39780
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-08-04
ASUS RT-AX55 Routers vulnerability
ASUS RT-AX55 routers contain an OS command injection vulnerability allowing authenticated remote attackers to execute arbitrary commands on affected devices.
Verdict
Today item — known-exploited.
A command injection flaw in ASUS RT-AX55 routers permits authenticated attackers to achieve arbitrary code execution. Active exploitation has been observed in the wild. Mitigation requires firmware updates and network access controls.
CISA KEV Yes · 2025-06-025EPSS 0.33878 (verify live)6CVSS 8.83CISA SSVC Exploitation: active · Automatable: no · Impact: total4
01
Is it exploitable?
— the evidence, ranked above the scoreReported 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 2025-06-02).
Probability (EPSS)
EPSS 0.33878 — 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:L/UI:N/S:U/C:H/I:H/A:H) · Affected: ASUS, RT-AX55 Routers. Confirm exact fixed builds in the vendor advisory.CVSS — CNA-assigned (CVE.org), version 3.1, set at disclosure.
Weakness (CWE)
Mapped to CWE-78 OS Command Injection — weakness family: Injection.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 630 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 gain initial access by obtaining valid credentials through phishing, credential stuffing, or default credentials on exposed management interfaces.
Business
Attackers can pivot from compromised routers to internal networks, establishing persistent backdoors and lateral movement paths.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I authenticate to the router's web interface or API and inject shell metacharacters into input fields to break out of intended command contexts.
Business
Arbitrary code execution on network infrastructure enables data exfiltration, traffic interception, and malware distribution across connected devices.
3
Lateral reach — past segmentation narrative 3
Attacker
I execute system commands with router privileges to modify configurations, install persistence mechanisms, or establish reverse shells.
Business
Compromised routers become undetectable attack platforms, undermining perimeter security and enabling long-term network 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