It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2022-2023-265 advisory.

    NLnet Labs Unbound, up to and including version 1.16.1 is vulnerable to a novel type of the ghost domain     names attack. The vulnerability works by targeting an Unbound instance. Unbound is queried for a     subdomain of a rogue domain name. The rogue nameserver returns delegation information for the subdomain     that updates Unbound's delegation cache. This action can be repeated before expiry of the delegation     information by querying Unbound for a second level subdomain which the rogue nameserver provides new     delegation information. Since Unbound is a child-centric resolver, the ever-updating child delegation     information can keep a rogue domain name resolvable long after revocation. From version 1.16.2 on, Unbound     checks the validity of parent delegation records before using cached delegation information.
    (CVE-2022-30698)

    NLnet Labs Unbound, up to and including version 1.16.1, is vulnerable to a novel type of the ghost domain     names attack. The vulnerability works by targeting an Unbound instance. Unbound is queried for a rogue     domain name when the cached delegation information is about to expire. The rogue nameserver delays the     response so that the cached delegation information is expired. Upon receiving the delayed answer     containing the delegation information, Unbound overwrites the now expired entries. This action can be     repeated when the delegation information is about to expire making the rogue delegation information ever-     updating. From version 1.16.2 on, Unbound stores the start time for a query and uses that to decide if the     cached delegation information can be overwritten. (CVE-2022-30699)

    A vulnerability named 'Non-Responsive Delegation Attack' (NRDelegation Attack) has been discovered in     various DNS resolving software. The NRDelegation Attack works by having a malicious delegation with a     considerable number of non responsive nameservers. The attack starts by querying a resolver for a record     that relies on those unresponsive nameservers. The attack can cause a resolver to spend a lot of     time/resources resolving records under a malicious delegation point where a considerable number of     unresponsive NS records reside. It can trigger high CPU usage in some resolver implementations that     continually look in the cache for resolved NS records in that delegation. This can lead to degraded     performance and eventually denial of service in orchestrated attacks. Unbound does not suffer from high     CPU usage, but resources are still needed for resolving the malicious delegation. Unbound will keep trying     to resolve the record until hard limits are reached. Based on the nature of the attack and the replies,     different limits could be reached. From version 1.16.3 on, Unbound introduces fixes for better performance     when under load, by cutting opportunistic queries for nameserver discovery and DNSKEY prefetching and     limiting the number of times a delegation point can issue a cache lookup for missing records.
    (CVE-2022-3204)

Tenable has extracted the preceding description block directly from the tested product security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Detections

Analytics

Amazon Linux 2022 : python3-unbound, unbound, unbound-anchor (ALAS2022-2023-265)

medium Nessus Plugin ID 170611

Version 1.1