ISC BIND 9.x < 9.9.9-P2 / 9.10.x < 9.10.4-P2 / 9.11.0a3 < 9.11.0b2 lwres Query DoS
Medium Nessus Plugin ID 92493
SynopsisThe remote name server is affected by a denial of service vulnerability.
DescriptionAccording to its self-reported version number, the installation of ISC BIND running on the remote name server is 9.x prior to 9.9.9-P2, 9.10.x prior to 9.10.4-P2, or 9.11.0a3 prior to 9.11.0b2. It is, therefore, affected by an error in the lightweight resolver (lwres) protocol implementation when resolving a query name that, when combined with a search list entry, exceeds the maximum allowable length. An unauthenticated, remote attacker can exploit this to cause a segmentation fault, resulting in a denial of service condition. This issue occurs when lwresd or the the named 'lwres' option is enabled.
SolutionUpgrade to ISC BIND version 9.9.8-P3 / 9.9.8-S4 / 9.10.3-P3 or later.
Note that BIND 9 version 9.9.9-S3 is available exclusively for eligible ISC Support customers.