Cisco Security Advisory
Click Icon to Copy Verbose Score
AV:A/AC:M/Au:N/C:P/I:P/A:N/E:U/RL:W/RC:C
-
Cisco IronPort Web Security Appliance (WSA) software contains a vulnerability that could allow an unauthenticated, remote attacker to conduct man-in-the-middle attacks against a targeted system.
The vulnerability is in the insecure SSL implementation of the affected operating system due to improper handling of SSL and Transport Layer Security (TLS) security certificates. The affected implementation could insecurely validate the certificate authority (CA) hierarchy and could trust illegitimate certificates.
An unauthenticated, remote attacker could exploit the vulnerability by using a legitimate certificate to generate a security certificate for a third-party domain. The attacker would then attempt to convince an affected user to visit the domain and establish an SSL connection with the domain by using the certificate provided. A successful attack could allow the attacker to conduct a man-in-the-middle attack against the affected user.
Cisco IronPort has confirmed the vulnerability; however, updates are not yet available. A workaround exists to mitigate the impact of this vulnerability.
A successful attack would require the attacker to have access to a network that is adjacent to the targeted user's system. This requirement would limit the likelihood of an attack.
A workaround exists that mitigates this vulnerability. The WSA can be configured to drop invalid certificates via the administrative GUI under Security Services -> HTTPS Proxy. The section "Invalid Certificate Handling" may be used to configure the handling of invalid certificates, enabling the administrator to configure the WSA to drop invalid certificates.
-
Cisco IronPort confirmed the vulnerability in bug ID 77544.
This vulnerability was discovered and reported to Cisco by Dell SecureWorks.
-
Administrators may consider configuring the WSA to drop invalid certificates.
Administrators are advised to contact the vendor regarding future updates and releases.
Administrators are advised to allow only trusted users to have network access.
Administrators may consider using IP-based access control lists (ACLs) to allow only trusted systems to access the affected systems.
Administrators are advised to monitor affected systems.
-
Updates are not available.
-
The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.
-
To learn about Cisco security vulnerability disclosure policies and publications, see the Security Vulnerability Policy. This document also contains instructions for obtaining fixed software and receiving security vulnerability information from Cisco.
-
Show LessVersion Description Section Status Date 1.0 Initial Release NA Final 2012-Apr-12
-
THIS DOCUMENT IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE INFORMATION ON THE DOCUMENT OR MATERIALS LINKED FROM THE DOCUMENT IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS DOCUMENT AT ANY TIME.
A stand-alone copy or paraphrase of the text of this document that omits the distribution URL is an uncontrolled copy, and may lack important information or contain factual errors. The information in this document is intended for end-users of Cisco products.