Every named instance configured to run as a recursive resolver maintains a cache database holding the responses to the queries it has recently sent to authoritative servers. The size limit for that cache database can be configured using the max-cache-size statement in the configuration file; it defaults to 90% of the total amount of memory available on the host. When the size of the cache reaches 7/8 of the configured limit, a cache-cleaning algorithm starts to remove expired and/or least-recently used RRsets from the cache, to keep memory use below the configured limit.
It has been discovered that the effectiveness of the cache-cleaning algorithm used in named can be severely diminished by querying the resolver for specific RRsets in a certain order, effectively allowing the configured max-cache-size limit to be significantly exceeded.
This issue affects BIND 9 versions 9.11.0 through 9.16.41, 9.18.0 through 9.18.15, 9.19.0 through 9.19.13, 9.11.3-S1 through 9.16.41-S1, and 9.18.11-S1 through 9.18.15-S1.
{
"unresolved_ranges": [
{
"cpes": [
"cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*",
"cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*",
"cpe:2.3:o:debian:debian_linux:12.0:*:*:*:*:*:*:*"
],
"vendor_product": "debian:debian_linux",
"extracted_events": [
{
"introduced": "10.0"
},
{
"last_affected": "10.0"
},
{
"introduced": "11.0"
},
{
"last_affected": "11.0"
},
{
"introduced": "12.0"
},
{
"last_affected": "12.0"
}
],
"source": "CPE_STRING"
},
{
"cpes": [
"cpe:2.3:o:fedoraproject:fedora:37:*:*:*:*:*:*:*",
"cpe:2.3:o:fedoraproject:fedora:38:*:*:*:*:*:*:*"
],
"vendor_product": "fedoraproject:fedora",
"extracted_events": [
{
"introduced": "37"
},
{
"last_affected": "37"
},
{
"introduced": "38"
},
{
"last_affected": "38"
}
],
"source": "CPE_STRING"
}
]
}{
"cpe": [
"cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:*",
"cpe:2.3:a:isc:bind:*:*:*:*:supported_preview:*:*:*"
],
"extracted_events": [
{
"introduced": "9.11.0"
},
{
"last_affected": "9.16.41"
},
{
"introduced": "9.11.3"
},
{
"introduced": "9.18.0"
},
{
"last_affected": "9.18.15"
},
{
"introduced": "9.18.11"
},
{
"introduced": "9.19.0"
},
{
"last_affected": "9.19.13"
}
],
"source": "CPE_RANGE"
}{
"cpe": [
"cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:*",
"cpe:2.3:a:isc:bind:*:*:*:*:supported_preview:*:*:*"
],
"extracted_events": [
{
"introduced": "9.11.0"
},
{
"last_affected": "9.16.41"
},
{
"introduced": "9.11.3"
},
{
"introduced": "9.18.0"
},
{
"last_affected": "9.18.15"
},
{
"introduced": "9.18.11"
},
{
"introduced": "9.19.0"
},
{
"last_affected": "9.19.13"
}
],
"source": "CPE_RANGE"
}