Vulnerability Note VU#412115
Network device drivers reuse old frame buffer data to pad packets
Many network device drivers reuse old frame buffer data to pad packets, resulting in an information leakage vulnerability that may allow remote attackers to harvest sensitive information from affected devices.
The Ethernet standard (IEEE 802.3) specifies a minimum data field size of 46 bytes. If a higher layer protocol such as IP provides packet data that is smaller than 46 bytes, the device driver must fill the remainder of the data field with a "pad". For IP datagrams, RFC1042 specifies that "the data field should be padded (with octets of zero) to meet the IEEE 802 minimum frame size requirements."
Researchers from @Stake have discovered that, contrary to the recommendations of RFC1042, many Ethernet device drivers fail to pad frames with null bytes. Instead, these device drivers reuse previously transmitted frame data to pad frames smaller than 46 bytes. This constitutes an information leakage vulnerability that may allow remote attackers to harvest potentially sensitive information. Depending upon the implementation of an affected device driver, the leaked information may originate from dynamic kernel memory, from static system memory allocated to the device driver, or from a hardware buffer located on the network interface card.
This vulnerability may also affect link layer networking protocols other than Ethernet.
This vulnerability allows remote attackers to harvest potentially sensitive information from network traffic. In some network environments, this vulnerability can also be used to circumvent technologies that divide networks into separate domains, such as VLANs and routers.
Apply a patch from your vendor
Use encryption to protect sensitive data
Systems Affected (Learn More)
|Vendor||Status||Date Notified||Date Updated|
|Debian||Affected||25 Jun 2002||25 Jul 2003|
|Guardian Digital Inc.||Affected||25 Jun 2002||24 Mar 2003|
|Hewlett-Packard Company||Affected||25 Jun 2002||25 Jul 2003|
|Intel||Affected||25 Jun 2002||21 Apr 2003|
|MandrakeSoft||Affected||25 Jun 2002||25 Jul 2003|
|Network Appliance||Affected||25 Jun 2002||08 Jan 2003|
|Red Hat Inc.||Affected||25 Jun 2002||31 Mar 2003|
|Sun Microsystems Inc.||Affected||25 Jun 2002||03 Feb 2003|
|Xerox Corporation||Affected||25 Jun 2002||09 Jun 2003|
|Apple Computer Inc.||Not Affected||25 Jun 2002||10 Jan 2003|
|Clavister||Not Affected||10 Jan 2003||16 Jan 2003|
|F5 Networks||Not Affected||25 Jun 2002||03 Jan 2003|
|Hitachi||Not Affected||03 Jan 2003||06 Jan 2003|
|IBM||Not Affected||25 Jun 2002||10 Jan 2003|
|National Semiconductor Corporation||Not Affected||09 Jan 2003||16 Jan 2003|
CVSS Metrics (Learn More)
The CERT/CC thanks Ofir Arkin and Josh Anderson for their discovery and analysis of this vulnerability.
This document was written by Jeffrey P. Lanza.
- CVE IDs: CAN-2003-0001
- Date Public: 06 Jan 2003
- Date First Published: 06 Jan 2003
- Date Last Updated: 25 Jul 2003
- Severity Metric: 13.50
- Document Revision: 34
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