An attacker might be able to trigger a use-after-free by sending crafted DNS queries to a DNSdist using the DNSQuestion:getEDNSOptions method in custom Lua code. In some cases DNSQuestion:getEDNSOptions might refer to a version of the DNS packet that has been modified, thus triggering a use-after-free and potentially a crash resulting in denial of service.

An attacker might be able to inject HTML content into the internal web dashboard by sending crafted DNS queries to a DNSdist instance where domain-based dynamic rules have been enabled via either DynBlockRulesGroup:setSuffixMatchRule or DynBlockRulesGroup:setSuffixMatchRuleFFI.

When the internal webserver is enabled (default is disabled), an attacker might be able to trick an administrator logged to the dashboard into visiting a malicious website and extract information about the running configuration from the dashboard. The root cause of the issue is a misconfiguration of the Cross-Origin Resource Sharing (CORS) policy.

An attacker might be able to trigger an out-of-bounds read by sending a crafted DNS response packet, when custom Lua code uses newDNSPacketOverlay to parse DNS packets. The out-of-bounds read might trigger a crash, leading to a denial of service, or access unrelated memory, leading to potential information disclosure.

An attacker might be able to trigger an out-of-bounds write by sending crafted DNS responses to a DNSdist using the DNSQuestion:changeName or DNSResponse:changeName methods in custom Lua code. In some cases the rewritten packet might become larger than the initial response and even exceed 65535 bytes, potentially leading to a crash resulting in denial of service.

When the earlyacldrop (earlyACLDrop in Lua) option is disabled (default is enabled) on a DNS over HTTPs frontend using the nghttp2 provider, the ACL check is skipped, allowing all clients to send DoH queries regardless of the configured ACL.

An attacker might be able to trick DNSdist into allocating too much memory while processing DNS over QUIC or DNS over HTTP/3 payloads, resulting in a denial of service. In setups with a large quantity of memory available this usually results in an exception and the QUIC connection is properly closed, but in some cases the system might enter an out-of-memory state instead and terminate the process.

An attacker can send a web request that causes unlimited memory allocation in the internal web server, leading to a denial of service. The internal web server is disabled by default.

An attacker can send a web request that causes unlimited memory allocation in the internal web server, leading to a denial of service. The internal web server is disabled by default.

An attacker can create a large number of concurrent DoQ or DoH3 connections, causing unlimited memory allocation in DNSdist and leading to a denial of service. DOQ and DoH3 are disabled by default.

A rogue backend can send a crafted UDP response with a query ID off by one related to the maximum configured value, triggering an out-of-bounds write leading to a denial of service.

A rogue backend can send a crafted SVCB response to a Discovery of Designated Resolvers request, when requested via either the autoUpgrade (Lua) option to newServer or autoupgrade (YAML) settings. DDR upgrade is not enabled by default.

A cached crafted response can cause an out-of-bounds read if custom Lua code calls getDomainListByAddress() or getAddressListByDomain() on a packet cache.

PRSD detection denial of service

A client might theoretically be able to cause a mismatch between queries sent to a backend and the received responses by sending a flood of perfectly timed queries that are routed to a TCP-only or DNS over TLS backend.

A client can trigger excessive memory allocation by generating a lot of errors responses over a single DoQ and DoH3 connection, as some resources were not properly released until the end of the connection.

A client can trigger a divide by zero error leading to crash by sending a crafted DNSCrypt query.

A client can trigger excessive memory allocation by generating a lot of queries that are routed to an overloaded DoH backend, causing queries to accumulate into a buffer that will not be released until the end of the connection.

When incoming DNS over HTTPS support is enabled using the nghttp2 provider, and queries are routed to a tcp-only or DNS over TLS backend, an attacker can trigger an assertion failure in DNSdist by sending a request for a zone transfer (AXFR or IXFR) over DNS over HTTPS, causing the process to stop and thus leading to a Denial of Service. DNS over HTTPS is not enabled by default, and backends are using plain DNS (Do53) by default.

Hi all, The issues fixed in these releases are:

Please feel free to contact me directly if you have any question.

Best regards, -- Remi Gacogne PowerDNS.COM BV - https://www.powerdns.com/

PowerDNS before 2.9.18, when allowing recursion to a restricted range of IP addresses, does not properly handle questions from clients that are denied recursion, which could cause a "blank out" of answers to those clients that are allowed to use recursion.

PowerDNS before 2.9.18, when running with an LDAP backend, does not properly escape LDAP queries, which allows remote attackers to cause a denial of service (failure to answer ldap questions) and possibly conduct an LDAP injection attack.

The DNSPacket::expand method in dnspacket.cc in PowerDNS before 2.9.17 allows remote attackers to cause a denial of service by sending a random stream of bytes.

The DNS implementation of PowerDNS 2.9.16 and earlier allows remote attackers to cause a denial of service via a compressed DNS packet with a label length byte with an incorrect offset, which could trigger an infinite loop.

The recursor in PowerDNS before 3.0.1 allows remote attackers to cause a denial of service (application crash) via malformed EDNS0 packets.

PowerDNS before 2.9.21.2 allows remote attackers to cause a denial of service (daemon crash) via a CH HINFO query.

PowerDNS Authoritative Server before 2.9.21.1 drops malformed queries, which might make it easier for remote attackers to poison DNS caches of other products running on other servers, a different issue than CVE-2008-1447 and CVE-2008-3217.

On Tue, Feb 13, 2024 at 12:06:42PM -0800, Alan Coopersmith wrote: On 2/13/24 06:07, Yorgos Thessalonikefs wrote: DNSSEC protocol vulnerabilities have been discovered that render various DNSSEC validators victims of Denial Of Service while trying to validate specially crafted DNSSEC responses.

There are two known vulnerabilities: CVE-2023-50387 (referred here as the KeyTrap vulnerability) and CVE-2023-50868 (referred here as the NSEC3 vulnerability). Similarly, dnsmasq 2.90 was published today to address these: https://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2024q1/017430.html And fixes for these two CVEs were merged into PowerDNS today:

https://github.com/PowerDNS/pdns/pull/13781

I hope PowerDNS will also be sending a proper advisory in here.

Alexander