Messages in this thread | | | Date | Wed, 3 Mar 2004 22:50:46 +0100 | From | GCS <> | Subject | question regarding BSD Security Advisory |
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Hi,
I was asked if something like this vulnerability may exists in Linux, or if is there any precautions for this? " Topic: many out-of-sequence TCP packets denial-of-service
I. Background
The Transmission Control Protocol (TCP) of the TCP/IP protocol suite provides a connection-oriented, reliable, sequence-preserving data stream service. When network packets making up a TCP stream (``TCP segments'') are received out-of-sequence, they are maintained in a reassembly queue by the destination system until they can be re-ordered and re-assembled.
II. Problem Description
FreeBSD does not limit the number of TCP segments that may be held in a reassembly queue.
III. Impact
A remote attacker may conduct a low-bandwidth denial-of-service attack against a machine providing services based on TCP (there are many such services, including HTTP, SMTP, and FTP). By sending many out-of-sequence TCP segments, the attacker can cause the target machine to consume all available memory buffers (``mbufs''), likely leading to a system crash. "
Cheers, GCS - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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