Allele Security Alert
Limiting simultaneous TCP clients is ineffective
Internet Systems Consortium (ISC)
BIND 9.9.0 to 9.10.8-P1
BIND 9.11.0 to 9.11.6
BIND 9.12.0 to 9.12.4
BIND Supported Preview Edition 9.9.3-S1 to 9.11.5-S3
BIND Supported Preview Edition 9.11.5-S5
BIND 9.13.0 to 9.13.7
BIND Supported Preview Edition 9.11.5-S6
BIND Supported Preview Edition 9.11.6-S1
Proof of concept
By design, BIND is intended to limit the number of TCP clients that can be connected at any given time. The number of allowed connections is a tunable parameter which, if unset, defaults to a conservative value for most servers. Unfortunately, the code which was intended to limit the number of simultaneous connections contains an error which can be exploited to grow the number of simultaneous connections beyond this limit.
CVE-2018-5743: Limiting simultaneous TCP clients is ineffective
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Last modified: April 27, 2019