In OpenStack Designate before 22.0.2, the mDNS handler performs pool-blind lookups when resolving record queries and NOTIFY requests. When two zones with the same name exist across different pools, the lookup fails with a deterministic error, causing the handler to return REFUSED for all DNS queries through that path. The handlenotify path is exploitable via a single unauthenticated UDP packet. This is independently reachable through the cross-tenant zone overlap described in a different recent CVE, and also affects legitimate same-tenant cross-pool configurations. BIND9 views do not mitigate this issue as mDNS is a shared service upstream of any view configuration.
In OpenStack Designate before 22.0.1, zone creation checks (issubzone, issuperzone, and the duplicate-zone DB constraint) are scoped to the target pool only. An authenticated user can bypass these checks by scheduling a zone to a different pool via the AttributeFilter scheduler, creating an overlapping zone that conflicts with another tenant's zone. This enables cross-tenant DNS hijack (redirecting traffic to attacker-controlled IPs) and DNS denial of service (NODATA responses). Exploitation requires a multi-pool deployment with AttributeFilter enabled in schedulerfilters, which is a non-default but documented and supported configuration for self-service tiering.
An access-control flaw was found in the OpenStack Designate component where private configuration information including access keys to BIND were improperly made world readable. A malicious attacker with access to any container could exploit this flaw to access sensitive information.
Description of problem:
The /etc/designate directory, /etc/designate/private, and /etc/designate/private/bind1.conf files are all world readable. This exposes the RNDC keys to anyone able access the container.
Inside the container: $ ls -al /etc/designate/ total 88 drwxr-xr-x. 1 root root 80 Sep 11 17:41 . drwxr-xr-x. 1 root root 55 Sep 11 17:41 .. -rw-r-----. 1 root designate 70205 Sep 11 16:31 designate.conf -rw-r-----. 1 root designate 6060 Sep 11 16:31 policy.yaml -rw-r--r--. 1 root root 2125 Sep 11 16:44 pools.yaml drwxr-xr-x. 2 root root 60 Sep 11 17:41 private -rw-r-----. 1 root designate 949 Jul 8 2022 rootwrap.conf
$ ls -al /etc/designate/private/ total 12 drwxr-xr-x. 2 root root 60 Sep 11 17:41 . drwxr-xr-x. 1 root root 80 Sep 11 17:41 .. -rw-r--r--. 1 root root 196 Sep 11 16:27 bind1.conf -rw-r--r--. 1 root root 196 Sep 11 16:27 bind2.conf -rw-r--r--. 1 root root 196 Sep 11 16:27 bind3.conf
On the overcloud host: $ ls -al /var/lib/config-data/puppet-generated/designate/etc/designate/private/bind1.conf -rw-r--r--. 1 root root 196 Sep 11 16:27 /var/lib/config-data/puppet-generated/designate/etc/designate/private/bind1.conf
Designate 2015.1.0 through 1.0.0.0b1 as packaged in OpenStack Kilo does not enforce RecordSets per domain, and Records per RecordSet quotas when processing an internal zone file transfer, which might allow remote attackers to cause a denial of service (infinite loop) via a crafted resource record set.
It was discovered that the Designate component in OpenStack would enter an infinite loop when processing an internal zone file transfer if a managed DNS zone included a resource record set whose size exceeded the limitations of the DNS protocol, leading to a denial of service. Only authenticated users with access to the Designate component can add such resource record sets.
Acknowledgements:
This issue was discovered by Florian Weimer of Red Hat Product Security.
Designate does not enforce the DNS protocol limit concerning record set sizes