Vulnerabilities > CVE-2017-6741 - Improper Restriction of Operations within the Bounds of a Memory Buffer vulnerability in Cisco IOS XE
Attack vector
NETWORK Attack complexity
LOW Privileges required
LOW Confidentiality impact
HIGH Integrity impact
HIGH Availability impact
HIGH Summary
The Simple Network Management Protocol (SNMP) subsystem of Cisco IOS 12.0 through 12.4 and 15.0 through 15.6 and IOS XE 2.2 through 3.17 contains multiple vulnerabilities that could allow an authenticated, remote attacker to remotely execute code on an affected system or cause an affected system to reload. An attacker could exploit these vulnerabilities by sending a crafted SNMP packet to an affected system via IPv4 or IPv6. Only traffic directed to an affected system can be used to exploit these vulnerabilities. The vulnerabilities are due to a buffer overflow condition in the SNMP subsystem of the affected software. The vulnerabilities affect all versions of SNMP: Versions 1, 2c, and 3. To exploit these vulnerabilities via SNMP Version 2c or earlier, the attacker must know the SNMP read-only community string for the affected system. To exploit these vulnerabilities via SNMP Version 3, the attacker must have user credentials for the affected system. All devices that have enabled SNMP and have not explicitly excluded the affected MIBs or OIDs should be considered vulnerable. Cisco Bug IDs: CSCve66658.
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.
Nessus
NASL family CISCO NASL id CISCO-SA-20170629-SNMP-IOS.NASL description According to its self-reported version and configuration, the Cisco IOS software running on the remote device is affected by multiple remote code execution vulnerabilities in the Simple Network Management Protocol (SNMP) subsystem due to multiple buffer overflow conditions. An unauthenticated, remote attacker can exploit these vulnerabilities, via a specially crafted SNMP packet, to execute arbitrary code. To exploit these vulnerabilities via SNMP version 2c or earlier, the attacker must know the SNMP read-only community string for the affected system. To exploit these vulnerabilities via SNMP version 3, the attacker must have user credentials for the affected system. last seen 2020-05-09 modified 2017-07-07 plugin id 101268 published 2017-07-07 reporter This script is Copyright (C) 2017-2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/101268 title Cisco IOS SNMP Packet Handling Remote Buffer Overflow Multiple RCE (cisco-sa-20170629-snmp) NASL family CISCO NASL id CISCO-SA-20170629-SNMP-IOSXE.NASL description According to its self-reported version and configuration, the Cisco IOS XE software running on the remote device is affected by multiple remote code execution vulnerabilities in the Simple Network Management Protocol (SNMP) subsystem due to multiple buffer overflow conditions. An unauthenticated, remote attacker can exploit these vulnerabilities, via a specially crafted SNMP packet, to execute arbitrary code. To exploit these vulnerabilities via SNMP version 2c or earlier, the attacker must know the SNMP read-only community string for the affected system. To exploit these vulnerabilities via SNMP version 3, the attacker must have user credentials for the affected system. last seen 2020-05-09 modified 2017-07-07 plugin id 101269 published 2017-07-07 reporter This script is Copyright (C) 2017-2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/101269 title Cisco IOS XE SNMP Packet Handling Remote Buffer Overflow Multiple RCE (cisco-sa-20170629-snmp)
References
- http://www.securityfocus.com/bid/99345
- http://www.securityfocus.com/bid/99345
- http://www.securitytracker.com/id/1038808
- http://www.securitytracker.com/id/1038808
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170629-snmp
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170629-snmp