US-CERT Current Activity

Insecure Loading of Dynamic Link Libraries in Windows Applications

2010-08-25T12:01:23-04:00

US-CERT is aware of a class of vulnerabilities related to how some Windows applications may load external dynamic link libraries (DLLs). When an application loads a DLL without specifying a fully qualified path name, Windows will attempt to locate the DLL by searching a defined set of directories. If an application does not securely load DLL files, an attacker may be able to cause the affected application to load an arbitrary library.

By convincing a user to open a file from a location that is under an attacker's control, such as a USB drive or network share, a remote attacker may be able to exploit this vulnerability. Exploitation of this vulnerability may result in the execution of arbitrary code.

Additional information regarding this vulnerability can be found in US-CERT Vulnerability Note VU#707943. US-CERT encourages users and administrators to review the vulnerability note and consider implementing the following workarounds until fixes are released by affected vendors

disable loading libraries from WebDAV and remote network shares
disable the WebClient service
block outgoing SMB traffic

Update: Microsoft has released Fix it tool 50522 to assist users in setting the registry key value introduced with Microsoft support article 2264107 to help reduce the risks posed by the DLL loading behavior described in VU#707943. Users and administrators are encouraged to review Microsoft support article 2264107, the Microsoft Security Research & Defense TechNet blog entry, and to consider using the Fix it tool to help reduce the risks. Users should be aware that setting the registry key value as described in the support article or via the Fix it tool may reduce the functionality of some third-party applications.

US-CERT will provide updates when additional details become available.

VMware Releases Updates for ESX Service Console Packages

2010-09-01T09:32:02-04:00

VMware has released security updates for multiple third party packages for the ESX Service Console. These updates address vulnerabilities in the perl, krb5, samba, tar, and cpio packages. Exploitation of these vulnerabilities may allow an attacker to execute arbitrary code, cause a denial-of-service condition, or bypass security restrictions.

US-CERT encourages users and administrators to review VMware security advisory VMSA-2010-0013 and apply any necessary updates to help mitigate the risks.

Cisco Releases Security Advisory for IOS XR Software Border Gateway Protocol

2010-08-31T08:40:53-04:00

Cisco has released a security advisory to address a vulnerability in the Cisco IOS XR Software Border Gateway Protocol feature. Exploitation of this vulnerability may result in the continuous resetting of BGP peering sessions, which may cause a denial-of-service condition for affected networks.

US-CERT encourages users and administrators to review Cisco security advisory cisco-sa-20100827-bgp and apply any necessary updates to help mitigate the risks.

RealNetworks Releases Update to Address Vulnerabilities in RealPlayer

2010-08-31T08:23:36-04:00

RealNetworks, Inc. has released an update for RealPlayer to address multiple vulnerabilities. These vulnerabilities may allow a remote, unauthenticated attacker to execute arbitrary code or obtain sensitive information.

US-CERT encourages users and administrators to review the RealNetworks, Inc. security advisory for these vulnerabilities and apply any necessary updates to help mitigate the risks.

Cisco Releases Advisories for Unified Communications Manager and Unified Presence

2010-08-25T13:53:24-04:00

Cisco has released security advisories to address multiple vulnerabilities affecting Unified Communications Manager and Unified Presence.

These vulnerabilities affect the processing of Session Initiation Protocol (SIP) messages. Exploitation of these vulnerabilities may allow an attacker to cause a denial-of-service condition, which could cause an interruption of voice services.

Cisco Unified Communications Manager users and administrators are encouraged to review Cisco security advisory cisco-sa-20100825-cucm and apply any necessary updates to help mitigate the risks. Cisco Unified Presence users and administrators are encouraged to review Cisco security advisory cisco-sa-20100825-cup and apply any necessary updates to help mitigate the risks.

APWG Fax Back Phishing Education Program

2010-08-25T13:16:42-04:00

In an effort to respond to a growing public threat by offline phishers that conduct various scams via fax, the Anti-phishing Working Group (APWG) has partnered with the Internal Revenue Service (IRS) to create the APWG Fax Back Phishing Education Program. This program is designed to provide telecommunications companies and Fax over Internet Protocol (FoIP) hosting firms with information that can be used to educate consumers about these types of scams. Offline phishing differs from traditional phishing in that it involves sending emails with attachments or direct faxes to individuals or businesses and is not done strictly online. Recipients of offline phishing scams are coerced to complete the fake documents and fax them back or be penalized.

In conjunction with IRS's Online Fraud Detection and Prevention (OFDP) group, APWG created a fax coversheet that can be downloaded by carriers and used to notify victims of offline phishing. This fax coversheet also provides links to other APWG resources which allow the victims to submit a complaint directly to the appropriate clearinghouse.

More information about the APWG Fax Back Phishing Education Program and the advisory fax coversheet can be found at the following

Adobe Releases Security Bulletin for Shockwave Player

2010-08-25T08:15:18-04:00

Adobe has released a security update to address multiple vulnerabilities affecting Shockwave Player 11.5.7.609 and earlier versions. These vulnerabilities may allow an attacker to execute arbitrary code.

US-CERT encourages users and administrators to review Adobe security bulletin APSB10-20 and upgrade to Adobe Shockwave Player 11.5.8.612 to help mitigate the risks.

Apple Releases Security Update 2010-005

2010-08-25T08:15:12-04:00

Apple has released security update 2010-005 to address multiple vulnerabilities affecting the ATS, CFNetwork, ClamAV, CoreGraphics, libsecurity, PHP, and Samba applications. These vulnerabilities may allow an attacker to execute arbitrary code, obtain sensitive information, cause a denial-of-service condition, or impersonate hosts within a domain.

US-CERT encourages users and administrators to review Apple article HT4312 and apply any necessary updates to help mitigate the risks.

Microsoft Releases Security Advisory

2010-08-24T11:42:18-04:00

Microsoft has released a security advisory indicating that it is aware of a remote attack vector for a class of vulnerabilities related to how applications load external dynamic link libraries (DLLs). If an application does not securely load DLL files, an attacker may be able to cause the application to load an arbitrary library. By convincing a user to open a file from a location that is under an attacker's control, such as a USB drive or network share, a remote attacker may be able exploit this vulnerability. Exploitation of this vulnerability may result in the execution of arbitrary code or elevation of privileges.

At this time, US-CERT is aware of reports of publicly available exploit code for this vulnerability.

US-CERT encourages users and administrators to review Microsoft security advisory 2269637 and consider implementing the workarounds listed in the document. Please note that these workarounds may reduce the functionality of the affected systems. Workarounds include

disabling the loading of libraries from WebDAV and remote network shares
disabling the WebClient service
blocking TCP ports 139 and 445 at the firewall

US-CERT will provide additional information as it becomes available.

VideoLAN Releases a Security Advisory for VLC Media Player

2010-08-20T10:47:03-04:00

VideoLAN has released a security advisory to address a vulnerability in VLC Media Player. This vulnerability may allow an attacker to execute arbitrary code or cause a denial-of-service condition. The updated release also addresses additional issues that could result in a denial-of-service attack.

US-CERT encourages users and administrators to review VideoLAN security advisory VideoLAN-SA-1004 and apply any necessary updates or workarounds to help mitigate the risks.