CVE-2021-34749 Multiple Cisco Products Server Name Identification Data Exfiltration Vulnerability
Unauthenticated attackers can bypass SSL filtering to exfiltrate data from compromised hosts via SNI requests in Cisco WSA, FTD, and Snort.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-34749?
CVE-2021-34749 is a medium-severity vulnerability in Cisco Secure Firewall Management Center, published on 18 Aug 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A vulnerability in Server Name Identification (SNI) request filtering of Cisco Web Security Appliance (WSA), Cisco Firepower Threat Defense (FTD), and the Snort detection engine could allow an unauthenticated, remote attacker to bypass filtering technology on an affected device and exfiltrate data from a compromised host. This vulnerability is due to inadequate filtering of the SSL handshake. An attacker could exploit this vulnerability by using data from the SSL client hello packet to communicate with an external server. A successful exploit could allow the attacker to execute a command-and-control attack on a compromised host and perform additional data exfiltration attacks.
Weakness: CWE-200
Which versions are affected by CVE-2021-34749?
It affects 3 products.
Products include Cisco Firepower Management Center Virtual Appliance Firmware, Cisco Ironport Web Security Appliance, Cisco Secure Firewall Management Center.
How do I fix CVE-2021-34749?
Apply the vendor's patch.
Is CVE-2021-34749 being exploited?
There is no known exploitation of CVE-2021-34749 in the wild and no public exploit code.
Sources
Also known as GHSA-x64m-mg53-f49j, UBUNTU-CVE-2021-34749.