| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| 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 auto_upgrade (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 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. |
| 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 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 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 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. |
| 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. |
| 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. |
| 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. |
