Cisco has disclosed a vulnerability in the Smart Install feature of the Cisco IOS Software and Cisco IOS XE Software. This vulnerability could allow an unauthenticated, remote attacker to execute arbitrary code on affected switches as well as leverage this vulnerability to cause the devices to reload, which will result in a temporary DoS while the devices are reloading.
The vulnerability is due to improper validation of packet data resulting in a buffer overflow. An attacker could exploit this vulnerability by sending a crafted Smart Install message to an affected switch on TCP port 4786. Only Smart Install client switches are affected by the vulnerability. Smart Install client functionality is enabled by default on Cisco IOS switches on software releases that have not been updated to address the Cisco bug ID CSCvd36820.
Researchers said they had identified roughly 250,000 vulnerable Cisco devices with TCP port 4786 open. Sophisticated nation-state groups have previously exploited vulnerabilities in Smart Install in their campaigns targeting critical infrastructure. There has not been any evidence indicating that CVE-2018-0171 has been exploited in malicious attacks.
Cisco has responded by releasing software updates to fix this critical vulnerability for affected switches. Switches that are running releases earlier than Cisco IOS Software Release 12.2(52)SE are not capable of running Smart Install.
Proficio Threat Intelligence Recommendations:
- Utilize the Cisco IOS Software Checker to determine if devices are vulnerable