#VU52734 Reachable Assertion in ISC BIND - CVE-2021-25214
Published: April 29, 2021
Vulnerability identifier: #VU52734
Vulnerability risk: Low
CVSSv4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2021-25214
CWE-ID: CWE-617
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerable software:
ISC BIND
ISC BIND
Software vendor:
ISC
ISC
Description
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to a reachable assertion when pressing IXFR queries. 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. 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.
Remediation
Install updates from vendor's website.