Vulnerabilities > CVE-2016-6366 - Classic Buffer Overflow vulnerability in Cisco products
Attack vector
NETWORK Attack complexity
LOW Privileges required
LOW Confidentiality impact
HIGH Integrity impact
HIGH Availability impact
HIGH Summary
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.
Vulnerable Configurations
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Buffer Overflow via Environment Variables This attack pattern involves causing a buffer overflow through manipulation of environment variables. Once the attacker finds that they can modify an environment variable, they may try to overflow associated buffers. This attack leverages implicit trust often placed in environment variables.
- Overflow Buffers Buffer Overflow attacks target improper or missing bounds checking on buffer operations, typically triggered by input injected by an attacker. As a consequence, an attacker is able to write past the boundaries of allocated buffer regions in memory, causing a program crash or potentially redirection of execution as per the attackers' choice.
- Client-side Injection-induced Buffer Overflow This type of attack exploits a buffer overflow vulnerability in targeted client software through injection of malicious content from a custom-built hostile service.
- Filter Failure through Buffer Overflow In this attack, the idea is to cause an active filter to fail by causing an oversized transaction. An attacker may try to feed overly long input strings to the program in an attempt to overwhelm the filter (by causing a buffer overflow) and hoping that the filter does not fail securely (i.e. the user input is let into the system unfiltered).
- MIME Conversion An attacker exploits a weakness in the MIME conversion routine to cause a buffer overflow and gain control over the mail server machine. The MIME system is designed to allow various different information formats to be interpreted and sent via e-mail. Attack points exist when data are converted to MIME compatible format and back.
Exploit-Db
| id | EDB-ID:40258 |
Metasploit
| description | This module patches the authentication functions of a Cisco ASA to allow uncredentialed logins. Uses improved shellcode for payload. |
| id | MSF:AUXILIARY/ADMIN/CISCO/CISCO_ASA_EXTRABACON |
| last seen | 2020-05-23 |
| modified | 2020-05-12 |
| published | 2016-09-22 |
| references | |
| reporter | Rapid7 |
| source | https://github.com/rapid7/metasploit-framework/blob/master//modules/auxiliary/admin/cisco/cisco_asa_extrabacon.rb |
| title | Cisco ASA Authentication Bypass (EXTRABACON) |
Nessus
| NASL family | CISCO |
| NASL id | CISCO-SN-CSCVA92151-ASA.NASL |
| description | According to its banner and configuration, the version of the remote Cisco Adaptive Security Appliance (ASA) device is affected by a remote code execution vulnerability, known as EXTRABACON, in the Simple Network Management Protocol (SNMP) code due to a buffer overflow condition. An authenticated, remote attacker can exploit this, via specially crafted IPv4 SNMP packets, to cause a denial of service condition or the execution of arbitrary code. Note that an attacker must know the SNMP community string in order to exploit the vulnerability. EXTRABACON is one of multiple Equation Group vulnerabilities and exploits disclosed on 2016/08/14 by a group known as the Shadow Brokers. |
| last seen | 2020-06-01 |
| modified | 2020-06-02 |
| plugin id | 93113 |
| published | 2016-08-25 |
| reporter | This script is Copyright (C) 2016-2019 and is owned by Tenable, Inc. or an Affiliate thereof. |
| source | https://www.tenable.com/plugins/nessus/93113 |
| title | Cisco ASA SNMP Packet Handling RCE (CSCva92151) (EXTRABACON) |
| code | |
The Hacker News
id THN:05BB2798ECF69CCBCACF84ECB5BF1A26 last seen 2018-01-27 modified 2016-08-20 published 2016-08-19 reporter Mohit Kumar source https://thehackernews.com/2016/08/nsa-hack-exploit.html title Leaked Exploits are Legit and Belong to NSA: Cisco, Fortinet and Snowden Docs Confirm id THN:425E35018D9F6A7EB2378DEB5FC8A65C last seen 2018-01-27 modified 2016-09-20 published 2016-09-19 reporter Mohit Kumar source https://thehackernews.com/2016/09/cisco-nsa-exploit.html title Cisco finds new Zero-Day Exploit linked to NSA Hackers
Related news
References
- http://blogs.cisco.com/security/shadow-brokers
- http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20160817-asa-snmp
- http://tools.cisco.com/security/center/viewErp.x?alertId=ERP-56516
- https://github.com/offensive-security/exploit-database-bin-sploits/raw/master/sploits/40258.zip
- https://zerosum0x0.blogspot.com/2016/09/reverse-engineering-cisco-asa-for.html
- http://www.securityfocus.com/bid/92521
- https://www.exploit-db.com/exploits/40258/
- http://www.securitytracker.com/id/1036637