Vulnerability · Published Aug 18, 2021 · Assigned by cisco
CVE-2021-34749Multiple Cisco Products Server Name Identification Data Exfiltration Vulnerability
Medium 5.8
In plain English
A medium-severity information exposure in Cisco Web Security Appliance (WSA) from Cisco. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.7% (higher than 77% of all known vulnerabilities).
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu:22.04:LTS | snort | no fix listed | UBUNTU-CVE-2021-34749 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Cisco | Cisco Web Security Appliance (WSA) | n/a |
Weakness: CWE-200 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
References
- 20210818 Multiple Cisco Products Server Name Identification Data Exfiltration Vulnerability vendor-advisory
- [debian-lts-announce] 20230210 [SECURITY] [DLA 3317-1] snort security update mailing-list
- DSA-5354 vendor-advisory