PatchFirst · Latest vulnerabilities
Vulnerabilities published for dnsdist in the last 30 days: 0. Listed in the KEV catalogue: 0.
Vulnerabilities: 34
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.
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.
When the early_acl_drop (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 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.
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 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.
In some circumstances, when DNSdist is configured to use the nghttp2 library to process incoming DNS over HTTPS queries, an attacker might be able to cause a denial of service by crafting a DoH exchange that triggers an unbounded I/O read loop, causing an unexpected consumption of CPU resources.
In some circumstances, when DNSdist is configured to allow an unlimited number of queries on a single, incoming TCP connection from a client, an attacker can cause a denial of service by crafting a TCP exchange that triggers an exhaustion of the stack and a crash of DNSdist, causing a denial of service. The remedy is: upgrade to the patched 1.9.10 version. A workaround is to restrict the maximum number of queries on incoming TCP connections to a safe value, like 50, via the setMaxTCPQueriesPerConnection setting. We would like to thank Renaud Allard for bringing this issue to our attention.
When DNSdist is configured to provide DoH via the nghttp2 provider, an attacker can cause a denial of service by crafting a DoH exchange that triggers an illegal memory access (double-free) and crash of DNSdist, causing a denial of service. The remedy is: upgrade to the patched 1.9.9 version. A workaround is to temporarily switch to the h2o provider until DNSdist has been upgraded to a fixed version. We would like to thank Charles Howes for bringing this issue to our attention.
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.
The HTTP/2 protocol allows a denial of service (server resource consumption) because request cancellation can reset many streams quickly, as exploited in the wild in August through October 2023.
An issue has been found in PowerDNS DNSDist before 1.3.3 allowing a remote attacker to craft a DNS query with trailing data such that the addition of a record by dnsdist, for example an OPT record when adding EDNS Client Subnet, might result in the trailing data being smuggled to the backend as a valid record while not seen by dnsdist. This is an issue when dnsdist is deployed as a DNS Firewall and used to filter some records that should not be received by the backend. This issue occurs only when either the 'useClientSubnet' or the experimental 'addXPF' parameters are used when declaring a new backend.
An issue has been found in dnsdist before 1.2.0 in the way EDNS0 OPT records are handled when parsing responses from a backend. When dnsdist is configured to add EDNS Client Subnet to a query, the response may contain an EDNS0 OPT record that has to be removed before forwarding the response to the initial client. On a 32-bit system, the pointer arithmetic used when parsing the received response to remove that record might trigger an undefined behavior leading to a crash.
dnsdist version 1.1.0 is vulnerable to a flaw in authentication mechanism for REST API potentially allowing CSRF attack.
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