CVE-2021-25214

Summary

In BIND 9.8.5 -> 9.8.8, 9.9.3 -> 9.11.29, 9.12.0 -> 9.16.13, and versions BIND 9.9.3-S1 -> 9.11.29-S1 and 9.16.8-S1 -> 9.16.13-S1 of BIND 9 Supported Preview Edition, as well as release versions 9.17.0 -> 9.17.11 of the BIND 9.17 development branch, when a vulnerable version of named receives a malformed IXFR triggering the flaw described above, the named process will terminate due to a failed assertion the next time the transferred secondary zone is refreshed.

Affected Software

VendorProductVersion RangeStatus
ISCBIND9Open Source Branch 9.8 9.8.5 through 9.8.8affected
ISCBIND9Open Source Branches 9.9 through 9.11 9.9.3 through versions before 9.11.30affected
ISCBIND9Open Source Branches 9.12 through 9.16 9.12.0 through versions before 9.16.14affected
ISCBIND9Supported Preview Branches 9.9-S through 9.11-S 9.9.3-S1 through versions before 9.11.30-S1affected
ISCBIND9Supported Preview Branch 9.16-S 9.16.8-S1 through versions before 9.16.14-S1affected
ISCBIND9Development Branch 9.17 9.17.0 through versiosn before 9.17.12affected

Weaknesses

  • Incremental zone transfers (IXFR) provide a way of transferring changed portion(s) of a zone between servers. An IXFR stream containing SOA records with an owner name other than the transferred zone's apex may cause the receiving named server to inadvertently remove the SOA record for the zone in question from the zone database. This leads to an assertion failure when the next SOA refresh query for that zone is made. Affects BIND 9.8.5 -> 9.8.8, 9.9.3 -> 9.11.29, 9.12.0 -> 9.16.13, and versions BIND 9.9.3-S1 -> 9.11.29-S1 and 9.16.8-S1 -> 9.16.13-S1 of BIND 9 Supported Preview Edition, as well as release versions 9.17.0 -> 9.17.11 of the BIND 9.17 development branch.

Workarounds

Disabling incremental zone transfers (IXFR) by setting request-ixfr no; in the desired configuration block (options, zone, or server) prevents the failing assertion from being evaluated.

ADP Enrichment

CVE Program Container

Additional References

References