Detections
Analytics
Cisco Web Security Appliance (WSA) Server Name Identification Data Exfiltration (cisco-sa-sni-data-exfil-mFgzXqLN)
high Nessus Plugin ID 152812
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Synopsis
The remote device is missing a vendor-supplied security patch.Description
According to its self-reported version, Cisco Web Security Appliance (WSA) is affected by a vulnerability in Server Name Identification (SNI) request filtering that allows 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.Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.
Solution
Upgrade to the relevant fixed version referenced in Cisco bug IDs CSCvy50873See Also
Plugin Details
Severity: High
ID: 152812
File Name: cisco-sa-sni-data-exfil-mFgzXqLN.nasl
Version: 1.6
Type: combined
Family: CISCO
Published: 8/25/2021
Updated: 8/27/2021
Supported Sensors: Nessus
Risk Information
VPR
Risk Factor: Medium
Score: 4.4
CVSS v2
Risk Factor: Medium
Base Score: 5
Temporal Score: 3.7
Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:N
CVSS Score Source: CVE-2021-34749
CVSS v3
Risk Factor: High
Base Score: 8.6
Temporal Score: 7.5
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N
Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C
Vulnerability Information
CPE: cpe:/h:cisco:web_security_appliance, cpe:/a:cisco:web_security_appliance, cpe:/o:cisco:web_security_appliance, cpe:/o:cisco:asyncos
Required KB Items: Host/AsyncOS/Cisco Web Security Appliance/DisplayVersion, Host/AsyncOS/Cisco Web Security Appliance/Version
Exploit Ease: No known exploits are available
Patch Publication Date: 8/18/2021
Vulnerability Publication Date: 8/18/2021
Reference Information
CVE: CVE-2021-34749