# CVE-2016-6366: Cisco Adaptive Security Appliance (ASA) SNMP Buffer Overflow Vulnerability

Source: https://junglewise.ai/threats/cve-2016-6366-cisco-adaptive-security-appliance-asa-snmp-buffer-overflow  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2022-05-24. Updated: 2026-05-10  
License: CC BY 4.0 with a link back

CVE-2016-6366 · Severity: critical · CVSS 8.8 · Exploited in the wild · Published 2022-05-24

A buffer overflow vulnerability in the SNMP code of Cisco ASA software allows remote authenticated attackers to execute arbitrary code or cause a system reload via crafted IPv4 SNMP packets. The vulnerability, also known as EXTRABACON, affects multiple Cisco security platforms including ASA 5500, PIX, and Firepower modules.

Technologies: [Cisco Adaptive Security Appliance (ASA)](https://junglewise.ai/threats/technologies/adaptive-security-appliance-asa), [Cisco Firepower Threat Defense (FTD)](https://junglewise.ai/threats/technologies/firepower-threat-defense-ftd). Vendors: [Cisco](https://junglewise.ai/threats/vendors/cisco).

## Quick answers

**Is CVE-2016-6366 exploited in the wild?** Yes. CVE-2016-6366 is known to be exploited in the wild, first recorded on 24 May 2022. Treat it as urgent.

**How severe is CVE-2016-6366?** Critical severity, with a CVSS score of 8.8, published 24 May 2022.

**Which products and versions are affected?** Cisco Adaptive Security Appliance (ASA) Software through 9.4.2.3; Cisco ASA 5500 Series Adaptive Security Appliances; Cisco ASA 5500-X Series Next-Generation Firewalls; Cisco ASA Services Module; and 5 more.

**Is there a fix for CVE-2016-6366?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2016-6366 attacked?** It is attacked over the network, in an operating system.

**Am I affected by CVE-2016-6366?** Check whether you run Cisco Adaptive Security Appliance (ASA) or Cisco Firepower Threat Defense (FTD). Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Affected products

- Cisco Adaptive Security Appliance (ASA) Software through 9.4.2.3
- Cisco ASA 5500 Series Adaptive Security Appliances
- Cisco ASA 5500-X Series Next-Generation Firewalls
- Cisco ASA Services Module
- Cisco ASA 1000V Cloud Firewall
- Cisco ASAv
- Cisco Firepower 9300 ASA Security Module
- Cisco PIX Firewalls
- Cisco Firewall Services Module (FWSM)

## Timeline

- 2016-08-17: advisory: Cisco Security Advisory published
- 2022-05-24: kev added: Added to CISA Known Exploited Vulnerabilities Catalog
- 2022-05-24: disclosed: NVD publication date

## Related threats

- [Cisco Adaptive Security Appliance (ASA) Cross-Site Scripting (XSS) Vulnerability](https://junglewise.ai/threats/cve-2014-2120-cisco-adaptive-security-appliance-asa-cross-site-scripting-xss)
- [Cisco ASA and FTD Denial-of-Service Vulnerability](https://junglewise.ai/threats/cve-2024-20481-cisco-asa-and-ftd-denial-of-service-vulnerability)
- [Cisco ASA and FTD Denial of Service Vulnerability](https://junglewise.ai/threats/cve-2024-20353-cisco-asa-and-ftd-denial-of-service-vulnerability)
- [Cisco ASA and FTD Privilege Escalation Vulnerability](https://junglewise.ai/threats/cve-2024-20359-cisco-asa-and-ftd-privilege-escalation-vulnerability)
- [SafePay ransomware campaign](https://junglewise.ai/threats/cve-2020-3259-cisco-asa-and-ftd-information-disclosure-vulnerability)