Denial of service in Cisco AsyncOS for Cisco Web Security Appliances

1) Resource exhaustion

EUVDB-ID: #VU14428

Risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2018-0410

CWE-ID: CWE-400 - Resource exhaustion

Exploit availability: No

Description

The vulnerability allows a remote attacker to cause DoS condition on the target system.

The vulnerability exists in the web proxy functionality of Cisco AsyncOS Software for Cisco Web Security Appliances due to improper management of memory resources for TCP connections. A remote attacker can establish a high number of TCP connections to the data interface of an affected device via IPv4 or IPv6, exhaust system memory and cause the system to stop processing new connections.

Mitigation

The vulnerability has been fixed in the versions 10.1.3-054, 10.5.2-072, 11.5.0-614.

Vulnerable software versions

Cisco AsyncOS for Web Security Appliances: 9.1 - 11.0

CPE2.3

• cpe:2.3:a:cisco_systems:cisco_asyncos_for_web_security_appliances:9.1:*:*:*:*:*:*:*
• cpe:2.3:a:cisco_systems:cisco_asyncos_for_web_security_appliances:10.1:*:*:*:*:*:*:*
• cpe:2.3:a:cisco_systems:cisco_asyncos_for_web_security_appliances:10.5:*:*:*:*:*:*:*

External links

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180815-wsa-dos

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.