Certain DNSSEC aspects of the DNS protocol (in RFC 4033, 4034, 4035, 6840, and related RFCs) allow remote attackers to cause a denial of service (CPU consumption) via one or more DNSSEC responses, aka the "KeyTrap" issue. One of the concerns is that, when there is a zone with many DNSKEY and RRSIG records, the protocol specification implies that an algorithm must evaluate all combinations of DNSKEY and RRSIG records.

NLnet Labs Unbound up to and including version 1.21.0 contains a vulnerability when handling replies with very large RRsets that it needs to perform name compression for. Malicious upstreams responses with very large RRsets can cause Unbound to spend a considerable time applying name compression to downstream replies. This can lead to degraded performance and eventually denial of service in well orchestrated attacks. The vulnerability can be exploited by a malicious actor querying Unbound for the specially crafted contents of a malicious zone with very large RRsets. Before Unbound replies to the query it will try to apply name compression which was an unbounded operation that could lock the CPU until the whole packet was complete. Unbound version 1.21.1 introduces a hard limit on the number of name compression calculations it is willing to do per packet. Packets that need more compression will result in semi-compressed packets or truncated packets, even on TCP for huge messages, to av…

NLnet Labs Unbound version 1.18.0 up to and including version 1.19.1 contain a vulnerability that can cause denial of service by a certain code path that can lead to an infinite loop. Unbound 1.18.0 introduced a feature that removes EDE records from responses with size higher than the client's advertised buffer size. Before removing all the EDE records however, it would try to see if trimming the extra text fields on those records would result in an acceptable size while still retaining the EDE codes. Due to an unchecked condition, the code that trims the text of the EDE records could loop indefinitely. This happens when Unbound would reply with attached EDE information on a positive reply and the client's buffer size is smaller than the needed space to include EDE records. The vulnerability can only be triggered when the 'ede: yes' option is used; non default configuration. From version 1.19.2 on, the code is fixed to avoid looping indefinitely.

NLnet Labs’ Routinator 0.9.0 up to and including 0.12.1 contains a possible path traversal vulnerability in the optional, off-by-default keep-rrdp-responses feature that allows users to store the content of responses received for RRDP requests. The location of these stored responses is constructed from the URL of the request. Due to insufficient sanitation of the URL, it is possible for an attacker to craft a URL that results in the response being stored outside of the directory specified for it.

NLnet Labs' Routinator up to and including version 0.12.1 may crash when trying to parse certain malformed RPKI objects. This is due to insufficient input checking in the bcder library covered by CVE-2023-39914.

NLnet Labs' bcder library up to and including version 0.7.2 panics while decoding certain invalid input data rather than rejecting the data with an error. This can affect both the actual decoding stage as well as accessing content of types that utilized delayed decoding.

NLnet Labs Krill supports direct access to the RRDP repository content through its built-in web server at the "/rrdp" endpoint. Prior to 0.12.1 a direct query for any existing directory under "/rrdp/", rather than an RRDP file such as "/rrdp/notification.xml" as would be expected, causes Krill to crash. If the built-in "/rrdp" endpoint is exposed directly to the internet, then malicious remote parties can cause the publication server to crash. The repository content is not affected by this, but the availability of the server and repository can cause issues if this attack is persistent and is not mitigated.

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 att…

In NLnet Labs Routinator 0.9.0 up to and including 0.11.2, due to a mistake in error handling, data in RRDP snapshot and delta files that isn’t correctly base 64 encoded is treated as a fatal error and causes Routinator to exit. Worst case impact of this vulnerability is denial of service for the RPKI data that Routinator provides to routers. This may stop your network from validating route origins based on RPKI data. This vulnerability does not allow an attacker to manipulate RPKI data.

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.