Cisco · IOS and IOS XE Software

CVE-2017-6739

Cisco IOS and IOS XE Software SNMP Remote Code Execution Vulnerability

Exploited in attacks High 8.8 Attack chance: 11%

What it is

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.

CISA: The Simple Network Management Protocol (SNMP) subsystem of Cisco IOS and IOS XE contains a vulnerability that could allow an authenticated, remote attacker to remotely execute code on an affected system or cause an affected system to reload.

What to do

Apply updates per vendor instructions.

Deadline for US federal agencies: March 24, 2022

Added to the CISA list: March 3, 2022
Published: July 17, 2017
Severity: High 8.8 CVSS 3.0
Chance of attacks in the next 30 days (EPSS): 11% in the top 4.2% of all known vulnerabilities
Weakness: CWE-119
More details: NVD · CVE.org · CISA

All references (1)

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170629-snmp

More exploited flaws from Cisco

Added	Vulnerability	Product	Severity	Attack chance
Apr 19, 2023	SNMP Remote Code ExecutionCVE-2017-6742	IOS and IOS XE Software	High 8.8	21%
Mar 3, 2022	IOS Software and Cisco IOS XE Software UDP Packet Processing Denial-of-ServiceCVE-2017-6627	IOS and IOS XE Software	High 7.5	6.2%
Mar 3, 2022	IOS Software and Cisco IOS XE Software Denial-of-ServiceCVE-2017-6663	IOS and IOS XE Software	Medium 6.5	2.1%
Mar 3, 2022	SNMP Remote Code ExecutionCVE-2017-6736	IOS and IOS XE Software	High 8.8	70%
Mar 3, 2022	SNMP Remote Code ExecutionCVE-2017-6737	IOS and IOS XE Software	High 8.8	45%
Mar 3, 2022	SNMP Remote Code ExecutionCVE-2017-6738	IOS and IOS XE Software	High 8.8	11%
Mar 3, 2022	SNMP Remote Code ExecutionCVE-2017-6740	IOS and IOS XE Software	High 8.8	11%
Mar 3, 2022	SNMP Remote Code ExecutionCVE-2017-6743	IOS and IOS XE Software	High 8.8	11%

All of them →

Sources: Known Exploited Vulnerabilities (CISA, public domain), CVE records (cve.org) and EPSS (FIRST). The chance of attacks is the EPSS estimate that someone will try to exploit the flaw in the next 30 days.