CVE-2017-6739

CVE-2017-6739 is a high-severity (CVSS 8.8) vulnerability in Cisco IOS and IOS XE Software. CISA added it to the Known Exploited Vulnerabilities catalog on March 3, 2022, which means exploitation in the wild has been confirmed; US federal agencies had to remediate it by March 24, 2022. CISA does not currently list it as used in ransomware campaigns. Cisco has 102 vulnerabilities in the KEV catalog, 7 of them linked to ransomware.

A vulnerability in the SNMP implementation of could allow an authenticated, remote attacker to cause a reload of the affected system or to remotely execute code. An attacker could exploit this vulnerability by sending a crafted SNMP packet to the affected device.  The vulnerability is due to a buffer overflow in the affected code area. The vulnerability affects all versions of SNMP (versions 1, 2c, and 3). The attacker must know the SNMP read only community string (SNMP version 2c or earlier) or the user credentials (SNMPv3). An exploit could allow the attacker to execute arbitrary code and obtain full control of the system or to cause a reload of the affected system. Only traffic directed to the affected system can be used to exploit this vulnerability.

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170629-snmp
• http://www.securityfocus.com/bid/99345
• http://www.securitytracker.com/id/1038808
• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170629-snmp
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2017-6739