Taofei Guo

**Name of the Vulnerable Software and Affected Versions** NLnet Labs Unbound versions prior to 1.25.1 **Description** An issue exists where promiscuous RRSets (Resource Record Sets) that complement DNS replies in the authority section can be used to trick the system into caching unauthorized records. An adversary can poison the cache by attaching such records to a reply via spoofed packets or fragmentation attacks. Specifically, a malicious actor can inject RRSets other than NS (Name Server), such as MX (Mail Exchange), accompanied by address records in a reply. The system may then accept and cache relative address records from the additional section if the authority RRSet possesses sufficient trust, such as in-zone data for the delegation point. **Recommendations** Update to version 1.25.1.

**Name of the Vulnerable Software and Affected Versions** Recursor (affected versions not specified) **Description** Improperly crafted zones may cause increased resource consumption. Additionally, crafted CNAME chains can lead to cache poisoning within the Recursor. **Recommendations** At the moment, there is no information about a newer version that contains a fix for this vulnerability.

**Name of the Vulnerable Software and Affected Versions** NLnet Labs Unbound versions up to and including 1.24.0 **Description** Unbound is susceptible to domain hijack attacks through the manipulation of DNS responses. Specifically, maliciously crafted NS Resource Record Sets (RRSets) included in replies can cause the resolver to update its delegation information, potentially leading to a zone transfer. An attacker could exploit this by injecting NS RRSets, possibly through packet spoofing or fragmentation attacks, causing Unbound to update its existing NS RRSet data due to the perceived trustworthiness of the injected information. **Recommendations** Update to version 1.24.1 or later.