Denial of service via crafted TCP exchange
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.5epss 0.6%
exploitation probability
0.6%top 54% of all CVEs
observed exploitation
nono source reports it
In some circumstances, when DNSdist is configured to allow an unlimited number of queries on a single, incoming TCP connection from a client, an attacker can cause a denial of service by crafting a TCP exchange that triggers an exhaustion of the stack and a crash of DNSdist, causing a denial of service.
The remedy is: upgrade to the patched 1.9.10 version.
A workaround is to restrict the maximum number of queries on incoming TCP connections to a safe value, like 50, via the setMaxTCPQueriesPerConnection setting.
We would like to thank Renaud Allard for bringing this issue to our attention.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected products
PowerDNS · DNSdist