Cisco Adaptive Security Appliance (ASA) SNMP Buffer Overflow Vulnerability
Cisco · Adaptive Security Appliance (ASA)
A buffer overflow in Cisco's Adaptive Security Appliance (ASA) Software, affecting ASA 5500, ASA 5500-X, ASA Services Module, ASA 1000V, ASAv, Firepower 9300 ASA Security Module, PIX, and FWSM devices, lies in the handling of IPv4 SNMP packets. An attacker who has network access to the device and valid authentication credentials can send crafted IPv4 SNMP packets to execute arbitrary code.
Buffer overflow in Cisco Adaptive Security Appliance (ASA) Software through 9.4.2.3 on ASA 5500, ASA 5500-X, ASA Services Module, ASA 1000V, ASAv, Firepower 9300 ASA Security Module, PIX, and FWSM devices allows remote authenticated users to execute arbitrary code via crafted IPv4 SNMP packets, aka Bug ID CSCva92151 or EXTRABACON.
- Exploited
- Yes, in CISA KEV
- Reports
- 0
- Tactics
- 2/15
How an attack unfolds
Based on MITRE ATT&CKA public catalogue of the techniques attackers use, maintained by MITRE. Patchfirst uses it to describe what attackers do with a vulnerability. mappings. Select a step to see the evidence.Exploitation timelineDated milestones for a CVE: when it was disclosed, when exploit code became public, when exploitation was confirmed, and when threat reports named it.
First seen exploited 3 days before it was disclosed. Public exploit code (Exploit-DB) was available the same day.
- First seen exploitedVulnCheck KEV evidence3 days before
- Added to CISA KEVEU database agrees+6 yrs
CISA KEV listing is when exploitation was confirmed, not necessarily the first attack.
MITRE ATT&CKA public catalogue of the techniques attackers use, maintained by MITRE. Patchfirst uses it to describe what attackers do with a vulnerability. techniques
2 TechniqueOne specific attacker behaviour in MITRE ATT&CK, such as T1190 “Exploit Public-Facing Application”. IDs with a dot, like T1059.004, are sub-techniques., grouped by TacticThe attacker’s goal at a stage of an attack in MITRE ATT&CK, such as Initial Access or Persistence. Each technique belongs to one or more tactics. in kill-chain order, 2 cited passages 2ExecutionTA0002
Arbitrary code execution on the device
allows remote authenticated users to execute arbitrary code
Lateral MovementTA0008
Remote exploitation via crafted network packets
allows remote authenticated users to execute arbitrary code via crafted IPv4 SNMP packets
Lower-confidence links (2)
These come from early or generic mappings, text matching, or contradict this CVE’s details (for example a public-facing technique on a bug that needs a user to open a file). Shown for completeness.
- Exploit Public-Facing ApplicationT1190 CTID attack_to_cve Phase 1 "Uncategorized" mapping (not staged by impact)
- Exploitation for Client ExecutionT1203 server-side bug exploitable without user interaction; client-execution technique does not fit
Detection
0 rules for this CVE · 110 general rules for its techniquesRules for this CVE
0Sigma ruleAn open, vendor-neutral detection rule for log data. Security teams convert Sigma rules into searches for their own SIEM. that reference CVE-2016-6366 directly.CVE-specific rules are not available in this build. Search SigmaHQ ↗
General rules for this CVE’s techniques
These detect the technique in general, not this specific vulnerability.
Exploitation of Remote ServicesT121015 general rules
- Zerologon Exploitation Using Well-known Toolscriticalstable
- Audit CVE Eventcriticaltest
- WannaCry Ransomware Activitycriticaltest
- OMIGOD HTTP No Authentication RCE - CVE-2021-38647highstable
- Exploitation Attempt Of CVE-2020-1472 - Execution of ZeroLogon PoChightest
- Exploitation Attempt Of CVE-2023-46214 Using Public POC Codehightest
- HackTool - SharpWSUS/WSUSpendu Executionhightest
- Possible Exploitation of Exchange RCE CVE-2021-42321hightest
Command and Scripting InterpreterT105995 general rules
- HackTool - Sliver C2 Implant Activity Patterncriticaltest
- Lazarus Group Activitycriticaltest
- REvil Kaseya Incident Malware Patternscriticaltest
- Turla Group Lateral Movementcriticaltest
- Windows Defender AMSI Trigger Detectedhighstable
- Windows Defender Threat Detectedhighstable
- Abusable DLL Potential Sideloading From Suspicious Locationhightest
- Add Insecure Download Source To Wingethightest
Sigma rules © SigmaHQ, Detection Rule License 1.1; linked, not reproduced.
What security researchers reported
Not named in any threat report yetAlso mentioned in 50 community threat pulses (AlienVault OTX)
Weaker evidencePulses are indicator collections that anyone can publish. A mention is not confirmation of exploitation.
- Actively_Exploited_Kev | Oct 29, 202628 Oct 2026
- Actively_Exploited_Kev | Oct 28, 202627 Oct 2026
- Actively_Exploited_Kev | Oct 27, 202626 Oct 2026
- Actively_Exploited_Kev | Oct 24, 202623 Oct 2026
- Actively_Exploited_Kev | Oct 23, 202622 Oct 2026
- Actively_Exploited_Kev | Oct 22, 202621 Oct 2026
- 44 more on OTX