| Current Security Incident
Activity Reported by U.S. - CERT |
Updated :
US-CERT is aware of publicly available exploit code for a cache poisoning vulnerability in common DNS implementations. Exploitation of this vulnerability may allow an attacker to cause a nameserver's clients to contact the incorrect, and possibly malicious hosts for particular services. As a result, web traffic, email and other important network data could be redirected to systems under the attacker's control.
US-CERT strongly urges administrators to patch affected systems immediately. Please review the following US-CERT documents for further details:
US-CERT will provide additional information as it becomes available.
US-CERT released a Current Activity entry and a Vulnerability Note on July 8, 2008 regarding deficiencies in DNS implementations. These deficiencies could leave an affected system vulnerable to cache poisoning. Technical details regarding this vulnerability have been posted to public websites. Attackers could use these details to construct exploit code. Users are encouraged to patch systems or apply workarounds immediately.
A number of patches implement source port randomization in the name server as a way to reduce the practicality of cache poisoning attacks. Administrators should be aware that in infrastructures where nameservers exist behind Network Address Translation (NAT) and Port Address Translation (PAT) devices, port randomization in the nameserver may be overwritten by the NAT/PAT device and a sequential port address could be allocated. This may weaken the protection offered by source port randomization in the nameserver.
US-CERT encourages users to consider one of the following workarounds:
- Place the nameserver outside of the NAT/PAT device in the network infrastructure.
- Configure the NAT/PAT device to perform source port randomization.
- Configure the NAT/PAT device to preserve the source port assigned by the nameserver.
Additional information can be found in US-CERT Vulnerability Note VU#800113.
More information will be provided as it becomes available.
US-CERT is aware of deficiencies in the DNS protocol. Implementations of this protocol may leave the affected system vulnerable to DNS cache poisoning attacks. If an attacker can successfully conduct a cache poisoning attack, they may be able to cause a nameserver's clients to contact the incorrect, and possibly malicious, hosts for particular services. This may allow an attacker to obtain sensitive information or mislead users into believing they are visiting a legitimate website.
UPDATE: Technical details regarding this vulnerability have been posted to public websites. Attackers could use these details to construct exploit code. Users are encouraged to patch vulnerable systems immediately.
US-CERT encourages users to review "VU#800113 - Multiple DNS implementations vulnerable to cache poisoning" and apply any necessary solutions listed in that document to help mitigate the risks.
US-CERT will provide additional information as it becomes available.
Research In Motion has released a Security Advisory to address a vulnerability in the BlackBerry Enterprise Server. This vulnerability is due to the improper processing of PDF files within the distiller component of the BlackBerry Attachment Service. By convincing a user to open a maliciously crafted PDF attachment on a BlackBerry smartphone, an attacker may be able to execute arbitrary code on the system running the BlackBerry Attachment Service.
US-CERT encourages users to review BlackBerry Security Advisory KB15766 and apply the resolution or implement the workarounds listed in the document to help mitigate the risk.
US-CERT will provide additional information as it becomes available.
Mozilla has released Firefox 3.0.1 to address three vulnerabilities. Exploitation of these vulnerabilities may allow a remote attacker to execute arbitrary code or cause a denial-of-service condition. One of these vulnerabilities may also affect Thunderbird and SeaMonkey. Two of these vulnerabilities were previously fixed in Firefox 2.0.0.16 as well; please see the US-CERT Current Activity entry Mozilla Releases Firefox 2.0.0.16 for additional information.
US-CERT encourages users to review the following Mozilla Foundation Security Advisories and upgrade to Firefox 3.0.1 or implement the workarounds provided in the documents to help mitigate the risks:
- MFSA 2008-34 : Remote code execution by overflowing CSS reference counter
- MFSA 2008-35 : Command-line URLs launch multiple tabs when Firefox not running
- MFSA 2008-36 : Crash with malformed GIF file on Mac OS X
WordPress has released version 2.6 to address approximately 194 bugs, some of which may be security related.
US-CERT encourages users to review the WordPress Blog entry related to the release of version 2.6 and upgrade to WordPress version 2.6 to help mitigate any risks.
Mozilla has released Firefox 2.0.0.16 to address two vulnerabilities. Exploitation of these vulnerabilities may allow a remote attacker to execute arbitrary code or cause a denial-of-service condition. One of these vulnerabilities may also affect Thunderbird and SeaMonkey.
US-CERT encourages users to review the following Mozilla Foundation Security Advisories and upgrade to a fixed version or implement the workarounds listed in the documents to help mitigate the risks.
MFSA 2008-34 : Remote code execution by overflowing CSS reference counter
MFSA 2008-35 : Command-line URLs launch multiple tabs when Firefox not running
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