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Cisco Web Security Appliance Multiple DoS Vulnerabilities

high Nessus Plugin ID 91338

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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 in Cisco AsyncOS due to improper validation of packets when parsing HTTP POST requests. An unauthenticated, remote attacker can exploit this, via a specially crafted POST request, to cause the proxy process to become unresponsive, resulting in the WSA reloading.
 (CVE-2016-1380)

 - A denial of service vulnerability exists in Cisco AsyncOS in the cached file-range request functionality due to a failure to free memory when a file range for cached content is requested through the WSA. An unauthenticated, remote attacker can exploit this, via multiple connections that request file ranges, to cause the WSA to stop passing traffic because of memory exhaustion. (CVE-2016-1381)

 - A denial of service vulnerability exists in Cisco AsyncOS due to improper allocation of memory for HTTP headers and expected HTTP payloads. An unauthenticated, remote attacker can exploit this, via specially crafted HTTP requests, to cause the proxy process to unexpectedly reload. (CVE-2016-1382)

 - A denial of service vulnerability exists in Cisco AsyncOS due to a failure to free client and server connection memory and system file descriptors when a certain HTTP response code is received in the HTTP request. An unauthenticated, remote attacker can exploit this, via specially crafted HTTP requests, to cause the WSA to stop accepting new connections because of memory exhaustion. (CVE-2016-1383)

Solution

Apply the relevant updates referenced in Cisco Security Advisories cisco-sa-20160518-wsa1, cisco-sa-20160518-wsa2, cisco-sa-20160518-wsa3 and cisco-sa-20160518-wsa4.

See Also

http://www.nessus.org/u?8ce8631d

http://www.nessus.org/u?430ceb05

http://www.nessus.org/u?708f68af

http://www.nessus.org/u?88b96b29

Plugin Details

Severity: High

ID: 91338

File Name: cisco-sa-20160518-wsa1_to_wsa4.nasl

Version: 1.8

Type: local

Family: CISCO

Published: 5/26/2016

Updated: 5/14/2021

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3.6

CVSS v2

Risk Factor: High

Base Score: 7.8

Temporal Score: 5.8

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

CVSS Score Source: CVE-2016-1383

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

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

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: 5/18/2016

Vulnerability Publication Date: 5/18/2016

Reference Information

CVE: CVE-2016-1380, CVE-2016-1381, CVE-2016-1382, CVE-2016-1383

BID: 90742, 90744, 90746, 90747