title: Memory leaks in code handling Diffie-Hellman key exchange via TKEY RRs (OpenSSL 3.0.0+ only)
description: An attacker can leverage this flaw to gradually erode available memory to the point where named crashes for lack of resources. Upon restart the attacker would have to begin again, but nevertheless there is the potential to deny service.
problem types: In BIND 9.18.0 -> 9.18.6 and versions 9.19.0 -> 9.19.4 of the BIND 9.19 development branch, changes between OpenSSL 1.x and OpenSSL 3.0 expose a flaw in named that causes a small memory leak in key processing when using TKEY records in Diffie-Hellman mode with OpenSSL 3.0.0 and later versions.
affected:
{
vendor: ISC
product: BIND9
versions:
version: Open Source Branch 9.18 9.18.0 through versions before 9.18.7, status: affected
version: Development Branch 9.19 9.19.0 through versions before 9.19.5, status: affected
}
metrics:
cvssV3_1: [
version: 3.1
vectorString: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
attackVector: NETWORK
attackComplexity: LOW
privilegesRequired: NONE
userInteraction: NONE
scope: UNCHANGED
confidentialityImpact: NONE
integrityImpact: NONE
availabilityImpact: HIGH
baseScore: 7.5
baseSeverity: HIGH
]
exploits: This flaw was discovered in internal testing. We are not aware of any active exploits.
solutions: Upgrade to the patched release most closely related to your current version of BIND: BIND 9.18.7 or BIND 9.19.5.
workarounds: There are no known workarounds. TKEY record processing in GSS-TSIG mode is not affected by this defect. The memory leak impacts authoritative DNS server TKEY record processing only. Client processing (resolver functions) do not trigger this defect.