NLnet Labs Unbound 1.12.0 up to and including 1.26.0 has a use-after-free vulnerability when compiled for DNS-over-HTTPs support with '--with-libnghttp2'. During failure code paths (i.e., RPZ drop query, jostle due to heavy traffic), a dropped DoH stream brings down the whole DoH session and does not account properly for other DoH streams in the same session. This leads to use-after-free in those code paths. If the prerequisites are satisfied (possible RPZ drop or heavy client traffic), a malicious actor can trigger the vulnerability with a single DoH connection and the appropriate traffic. Impact is limited as the reads are not user controlled and the use-after-free leads to early returns. However, a hardened allocator can catch the use-after-free and controllably terminate the process resulting to denial of service.

NLnet Labs Unbound 1.12.0 up to and including 1.26.0 has a use-after-free vulnerability when compiled for DNS-over-HTTPs support with '--with-libnghttp2'. During failure code paths (i.e., RPZ drop query, jostle due to heavy traffic), a dropped DoH stream brings down the whole DoH session and does not account properly for other DoH streams in the same session. This leads to use-after-free in those code paths. If the prerequisites are satisfied (possible RPZ drop or heavy client traffic), a malicious actor can trigger the vulnerability with a single DoH connection and the appropriate traffic. Impact is limited as the reads are not user controlled and the use-after-free leads to early returns. However, a hardened allocator can catch the use-after-free and controllably terminate the process resulting to denial of service.

libunbound8-1.26.1-1.1 on GA media

unbound: Unbound: Denial of Service via 'serve-expired' code path bypass unbound: Unbound: ZONEMD verification bypass due to asynchronous DNSSEC resolution unbound: Unbound: Denial of Service via use-after-free in DoQ stream output buffer unbound: Unbound: Denial of Service via continuous queries on TCP/DoT connection unbound: Unbound: Heap buffer overflow via malicious DNSSEC response unbound: Unbound: Heap buffer overflow and possible Remote Code Execution when digesting DNSKEY unbound: Unbound: Remote Code Execution Vulnerability in CNAME Synthesis unbound: Unbound: Denial of Service via use-after-free in DoH stream cleanup unbound: Unbound: Denial of Service via algorithmic complexity attacks on DNSSEC

Affected: Ubuntu:Pro:14.04:LTS: unbound, Ubuntu:Pro:16.04:LTS: unbound, Ubuntu:Pro:18.04:LTS: unbound, Ubuntu:Pro:20.04:LTS: unbound, Ubuntu:22.04:LTS: unbound, Ubuntu:24.04:LTS: unbound, Ubuntu:26.04:LTS: unbound

NLnet Labs Unbound 1.12.0 up to and including 1.26.0 has a use-after-free vulnerability when compiled for DNS-over-HTTPs support with '--with-libnghttp2'. During failure code paths (i.e., RPZ drop query, jostle due to heavy traffic), a dropped DoH stream brings down the whole DoH session and does not account properly for other DoH streams in the same session. This leads to use-after-free in those code paths. If the prerequisites are satisfied (possible RPZ drop or heavy client traffic), a malicious actor can trigger the vulnerability with a single DoH connection and the appropriate traffic. Impact is limited as the reads are not user controlled and the use-after-free leads to early returns. However, a hardened allocator can catch the use-after-free and controllably terminate the process resulting to denial of service.

Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in Unbound ausnutzen, um Sicherheitsmaßnahmen zu umgehen, Speicher zu korrumpieren, einen Denial of Service zu verursachen oder Code auszuführen.