Certain DNSSEC aspects of the DNS protocol (in RFC 4033, 4034, 4035, 6840, and related RFCs) allow remote attackers to cause a denial of service (CPU consumption) via one or more DNSSEC responses, aka the "KeyTrap" issue. One of the concerns is that, when there is a zone with many DNSKEY and RRSIG records, the protocol specification implies that an algorithm must evaluate all combinations of DNSKEY and RRSIG records.
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.
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.
Hi all,
The full security advisory is provided below, and can also be found at https://www.dnsdist.org/security-advisories/powerdns-advisory-for-dnsdist-2025-02.html
A minimal patch can also be found here: https://downloads.powerdns.com/patches/2025-02/
Please feel free to contact me directly if you have any question. - CVE: CVE-2025-30194 - Date: 2025-04-29T12:00:00+02:00 - Discovery date: 2025-04-25T21:55:00+02:00 - Affects: PowerDNS DNSdist from 1.9.0 up to 1.9.8 - Not affected: PowerDNS DNSdist 1.9.9 and versions before 1.9.0 - Severity: High - Impact: Denial of service - Risk of system compromise: None - CWE: CWE-416 - CVSS: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Last affected: 1.9.8 - First fixed: 1.9.9 - Internal ID: 297
The remedy is: upgrade to the patched 1.9.9 version.
Best regards, -- Remi Gacogne PowerDNS.COM BV - https://www.powerdns.com/
An attacker can publish a zone containing specific Resource Record Sets. Processing and caching results for these sets can lead to an illegal memory accesses and crash of the Recursor, causing a denial of service.
The remedy is: upgrade to the patched 5.2.1 version.
We would like to thank Volodymyr Ilyin for bringing this issue to our attention.
A remote attacker might be able to cause infinite recursion in PowerDNS Recursor 4.8.0 via a DNS query that retrieves DS records for a misconfigured domain, because QName minimization is used in QM fallback mode. This is fixed in 4.8.1.
Denial of service vulnerability in PowerDNS Recursor allows authoritative servers to be marked unavailable.This issue affects Recursor: through 4.6.5, through 4.7.4 , through 4.8.3.
In PowerDNS Authoritative Server before 4.4.3, 4.5.x before 4.5.4, and 4.6.x before 4.6.1 and PowerDNS Recursor before 4.4.8, 4.5.x before 4.5.8, and 4.6.x before 4.6.1, insufficient validation of an IXFR end condition causes incomplete zone transfers to be handled as successful transfers.
An issue has been found in PowerDNS Authoritative Server before 4.3.1 where an authorized user with the ability to insert crafted records into a zone might be able to leak the content of uninitialized memory.
A vulnerability was found in PowerDNS Authoritative Server before 4.0.7 and before 4.1.7. An insufficient validation of data coming from the user when building a HTTP request from a DNS query in the HTTP Connector of the Remote backend, allowing a remote user to cause a denial of service by making the server connect to an invalid endpoint, or possibly information disclosure by making the server connect to an internal endpoint and somehow extracting meaningful information about the response
An issue has been found in PowerDNS Recursor versions 4.1.x before 4.1.9 where records in the answer section of responses received from authoritative servers with the AA flag not set were not properly validated, allowing an attacker to bypass DNSSEC validation.
An issue has been found in PowerDNS Recursor versions after 4.1.3 before 4.1.9 where Lua hooks are not properly applied to queries received over TCP in some specific combination of settings, possibly bypassing security policies enforced using Lua.
An issue has been found in PowerDNS Recursor from 4.0.0 up to and including 4.1.4. A remote attacker sending a DNS query for a meta-type like OPT can lead to a zone being wrongly cached as failing DNSSEC validation. It only arises if the parent zone is signed, and all the authoritative servers for that parent zone answer with FORMERR to a query for at least one of the meta-types. As a result, subsequent queries from clients requesting DNSSEC validation will be answered with a ServFail.
Last updated 14 January 2025
Last updated 14 January 2025
A cross-site scripting issue has been found in the web interface of PowerDNS Recursor from 4.0.0 up to and including 4.0.6, where the qname of DNS queries was displayed without any escaping, allowing a remote attacker to inject HTML and Javascript code into the web interface, altering the content.
When api-config-dir is set to a non-empty value, which is not the case by default, the API in PowerDNS Recursor 4.x up to and including 4.0.6 and 3.x up to and including 3.7.4 allows an authorized user to update the Recursor's ACL by adding and removing netmasks, and to configure forward zones. It was discovered that the new netmask and IP addresses of forwarded zones were not sufficiently validated, allowing an authenticated user to inject new configuration directives into the Recursor's configuration.
An issue has been found in the DNSSEC validation component of PowerDNS Recursor from 4.0.0 and up to and including 4.0.6, where the signatures might have been accepted as valid even if the signed data was not in bailiwick of the DNSKEY used to sign it. This allows an attacker in position of man-in-the-middle to alter the content of records by issuing a valid signature for the crafted records.
dnsdist version 1.1.0 is vulnerable to a flaw in authentication mechanism for REST API potentially allowing CSRF attack.
commonstartup.cc in PowerDNS (aka pdns) Authoritative Server before 2.9.22.5 and 3.x before 3.0.1 allows remote attackers to cause a denial of service (packet loop) via a crafted UDP DNS response.
An issue has been found in the DNSSEC parsing code of PowerDNS Recursor from 4.0.0 up to and including 4.0.6 leading to a memory leak when parsing specially crafted DNSSEC ECDSA keys. These keys are only parsed when validation is enabled by setting dnssec to a value other than off or process-no-validate (default).
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.
PowerDNS Recursor before 3.1.6 does not always use the strongest random number generator for source port selection, which makes it easier for remote attack vectors to conduct DNS cache poisoning. NOTE: this is related to incomplete integration of security improvements associated with addressing CVE-2008-1637.
PowerDNS Recursor before 3.1.5 uses insufficient randomness to calculate (1) TRXID values and (2) UDP source port numbers, which makes it easier for remote attackers to poison a DNS cache, related to (a) algorithmic deficiencies in rand and random functions in external libraries, (b) use of a 32-bit seed value, and (c) choice of the time of day as the sole seeding information.
Buffer overflow in PowerDNS Recursor before 3.1.7.2 allows remote attackers to cause a denial of service (daemon crash) or possibly execute arbitrary code via crafted packets.
Unspecified vulnerability in PowerDNS Recursor before 3.1.7.2 allows remote attackers to spoof DNS data via crafted zones.
The resolver in PowerDNS Recursor (aka pdnsrecursor) 3.3 overwrites cached server names and TTL values in NS records during the processing of a response to an A record query, which allows remote attackers to trigger continued resolvability of revoked domain names via a "ghost domain names" attack.
PowerDNS Recursor before 3.6.2 does not limit delegation chaining, which allows remote attackers to cause a denial of service ("performance degradations") via a large or infinite number of referrals, as demonstrated by resolving domains hosted by ezdns.it.
Unspecified vulnerability in PowerDNS Recursor (aka pdnsrecursor) 3.6.x before 3.6.1 allows remote attackers to cause a denial of service (crash) via an unknown sequence of malformed packets.
The label decompression functionality in PowerDNS Recursor before 3.6.4 and 3.7.x before 3.7.3 and Authoritative (Auth) Server before 3.3.3 and 3.4.x before 3.4.5 allows remote attackers to cause a denial of service (CPU consumption or crash) via a request with a long name that refers to itself. NOTE: this vulnerability exists because of an incomplete fix for CVE-2015-1868.