Threats / Cisco / CVE-2016-6366
CVE-2016-6366
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-08-04
Cisco Adaptive Security Appliance (ASA) vulnerability
A buffer overflow in Cisco ASA SNMP code allows remote code execution or system reload without authentication.
Verdict
Today item — known-exploited.
This vulnerability enables unauthenticated remote attackers to execute arbitrary code or crash Cisco ASA devices via malformed SNMP packets. The high EPSS score and active exploitation reflect significant risk to network perimeter security.
CISA KEV Yes · 2022-05-244EPSS 0.87565 (verify live)5Exploit Weaponized · public PoC6CVSS 8.8 (CISA)3CISA SSVC Exploitation: active · Automatable: no · Impact: total3
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
7 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 2022-05-24).
Probability (EPSS)
EPSS 0.87565 — 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: Cisco, Adaptive Security Appliance (ASA). Confirm exact fixed builds in the vendor advisory.CVSS — CISA-assigned via the ADP container (CVE.org), version 3.1; the CNA left no metrics, so CISA's own score is used ahead of NVD.
Weakness (CWE)
Mapped to CWE-119 Memory Buffer Bounds Error — weakness family: Memory safety.CWE assignment from the public NVD record (may be stale); 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 2105 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 public proof-of-concept / detection template). Catalog entries: Metasploit module. 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.
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 malformed SNMP packet targeting the buffer overflow in ASA SNMP processing.
Business
Network perimeter security is compromised, enabling potential lateral movement into protected infrastructure.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I send the packet to an ASA device with SNMP enabled, triggering code execution with device privileges.
Business
Attackers gain control of security appliances, bypassing firewall rules and VPN protections.
3
Lateral reach — past segmentation narrative 3
Attacker
I establish persistence or pivot to internal systems, or I crash the ASA to disrupt network operations.
Business
Business continuity is threatened through either data exfiltration, ransomware deployment, or denial of service.
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