Cisco Web Security Appliance Multiple Vulnerabilities

critical Nessus Plugin ID 86916

Synopsis

The remote security appliance is missing a vendor-supplied patch.

Description

According to its self-reported version, the Cisco Web Security Appliance (WSA) running on the remote host is affected by the following vulnerabilities :

- A denial of service vulnerability exists due to a failure to free memory objects when retrieving data from the proxy server to terminate a TCP connection. An unauthenticated, remote attacker can exploit this, by opening a large number of proxy connections, to cause exhaustion of memory, resulting in the WSA to stop passing traffic. (CVE-2015-6292)

- A denial of service vulnerability exists due to a failure to free memory when a file range is requested.
An unauthenticated, remote attacker can exploit this, by opening multiple connections that request file ranges, to cause exhaustion of memory, resulting in the WSA to stop passing traffic. (CVE-2015-6293)

- A flaw exists in the certificate generation process due to improper validation of parameters passed to the affected scripts of the web interface. An authenticated, remote attacker can exploit this, via crafted arguments to the parameters, to execute arbitrary commands on the system with root level privileges. (CVE-2015-6298)

- A denial of service vulnerability exists due to improper handling of TCP packets sent at a high rate. An unauthenticated, remote attacker can exploit this to exhaust all available memory, preventing any more TCP connections from being accepted. (CVE-2015-6321)

Solution

Apply the relevant updates referenced in Cisco Security Advisories cisco-sa-20151104-aos, cisco-sa-20151104-wsa, cisco-sa-20151104-wsa1, and cisco-sa-20151104-wsa2.

See Also

http://www.nessus.org/u?561dad7b

http://www.nessus.org/u?9afe6628

http://www.nessus.org/u?8b233cd4

http://www.nessus.org/u?6af33d45

Plugin Details

Severity: Critical

ID: 86916

File Name: cisco-sa-20151104-aos_wsa.nasl

Version: 1.8

Type: local

Family: CISCO

Published: 11/18/2015

Updated: 5/20/2021

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 5.9

CVSS v2

Risk Factor: High

Base Score: 9

Temporal Score: 6.7

Vector: CVSS2#AV:N/AC:L/Au:S/C:C/I:C/A:C

CVSS Score Source: CVE-2015-6298

CVSS v3

Risk Factor: Critical

Base Score: 9.9

Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

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: 11/4/2015

Vulnerability Publication Date: 11/4/2015

Reference Information

CVE: CVE-2015-6292, CVE-2015-6293, CVE-2015-6298, CVE-2015-6321