Tags give the ability to mark specific points in history as being important
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release-1.19.2
5b37cd6e · ·Unbound 1.19.2 This security release fixes CVE-2024-1931. NLnet Labs Unbound version 1.18.0 up to and including version 1.19.1 contain a vulnerability that can cause denial of service by a certain code path that can lead to an infinite loop. Unbound 1.18.0 introduced a feature that removes EDE records from responses with size higher than the client's advertised buffer size. Before removing all the EDE records however, it would try to see if trimming the extra text fields on those records would result in an acceptable size while still retaining the EDE codes. Due to an unchecked condition, the code that trims the text of the EDE records could loop indefinitely. This happens when Unbound would reply with attached EDE information on a positive reply and the client's buffer size is smaller than the needed space to include EDE records. The vulnerability can only be triggered when the 'ede: yes' option is used; non default configuration. From version 1.19.2 on, the code is fixed to avoid looping indefinitely. We would like to thank Fredrik Pettai and Patrik Lundin from SUNET for notifying us about the issue and working with us to identify the vulnerability. Bug Fixes: - Fix CVE-2024-1931, Denial of service when trimming EDE text on positive replies.
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release-1.19.1
c6dd1e11 · ·Unbound 1.19.1 This security release fixes two DNSSEC validation vulnerabilities: CVE-2023-50387 (referred here as the KeyTrap vulnerability) and CVE-2023-50868 (referred here as the NSEC3 vulnerability). The KeyTrap vulnerability works by using a combination of Keys (also colliding Keys), Signatures and number of RRSETs on a malicious zone. Answers from that zone can force a DNSSEC validator down a very CPU intensive and time costly validation path. The NSEC3 vulnerability uses specially crafted responses on a malicious zone with multiple NSEC3 RRSETs to force a DNSSEC validator down a very CPU intensive and time costly NSEC3 hash calculation path. Both can force Unbound to spend an enormous time (comparative to regular traffic) validating a single specially crafted DNSSEC response while everything else is on hold for that thread. A trivially orchestrated attack could render all threads busy with such responses leading to denial of service. From version 1.19.1 on, Unbound introduces suspension on DNSSEC response validations that seem to require more attempts than Unbound is willing to make per response validation run. Suspension means that Unbound will continue with other work before resuming a suspended validation offering CPU time between validation resumptions to other tasks. There is a backoff timer when suspending which is further influenced by the number of suspends already used and the amount of work currently in Unbound. The introduced builtin limits in Unbound are: - Max 4 DNSSEC key collissions are allowed when building chain of trust. More than that without a secure key treats the delegation as bogus. - 8 validation attempts per RRSET (combination of keys + signatures). If more are needed and Unbound has yet to find a valid signature the RRSET is treated as bogus. - More than 8 validation attempts per answer will suspend validation. - 8 NSEC3 hash calculations are allowed before suspension. More than that will suspend validation. - The limit of total suspensions is 16 after which the query will error out. Any completed RRSET validations populate the cache for use in future queries. While under attack Unbound could show higher CPU load because of the needed validations but the suspend strategy would guarantee the CPU is not locked on any particular validation task. We would like to thank Elias Heftrig, Haya Schulmann, Niklas Vogel, and Michael Waidner from the German National Research Center for Applied Cybersecurity ATHENE for discovering and responsibly disclosing the KeyTrap vulnerability. We would like to thank Petr Špaček from ISC for discovering and responsibly disclosing the NSEC3 vulnerability. Bug Fixes - Fix CVE-2023-50387, DNSSEC verification complexity can be exploited to exhaust CPU resources and stall DNS resolvers. - Fix CVE-2023-50868, NSEC3 closest encloser proof can exhaust CPU.
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release-1.19.0
3352b109 · ·Unbound 1.19.0 This release fixes a number of bugs, and adds some smaller features. The redis-logical-db option and cachedb-no-store option can be used for cachedb configuration. The disable-edns-do option can be used for working around broken network parts. For DNS64 there is fallback to plain AAAA when no A record exists. There is a bug fix that when the UDP interface keeps returning that sending is not possible, unbound does not loop endlessly and waits for the condition to go away. Resource records of type A and AAAA that are an inappropriate length are removed from responses. This hardens against bad content. Features - Fix #850: [FR] Ability to use specific database in Redis, with new redis-logical-db configuration option. - Merge #944: Disable EDNS DO. Disable the EDNS DO flag in upstream requests. This can be helpful for devices that cannot handle DNSSEC information. But it should not be enabled otherwise, because that would stop DNSSEC validation. The DNSSEC validation would not work for Unbound itself, and also not for downstream users. Default is no. The option is disable-edns-do: no - Expose the script filename in the Python module environment 'mod_env' instead of the config_file structure which includes the linked list of scripts in a multi Python module setup; fixes #79. - Expose the configured listening and outgoing interfaces, if any, as a list of strings in the Python 'config_file' class instead of the current Swig object proxy; fixes #79. - Mailing list patches from Daniel Gröber for DNS64 fallback to plain AAAA when no A record exists for synthesis, and minor DNS64 code refactoring for better readability. - Merge #951: Cachedb no store. The cachedb-no-store: yes option is used to stop cachedb from writing messages to the backend storage. It reads messages when data is available from the backend. The default is no. Bug Fixes - Fix for version generation race condition that ignored changes. - Fix #942: 1.18.0 libunbound DNS regression when built without OpenSSL. - Fix for WKS call to getservbyname that creates allocation on exit in unit test by testing numbers first and testing from the services list later. - Fix autoconf 2.69 warnings in configure. - Fix #927: unbound 1.18.0 make test error. Fix make test without SHA1. - Merge #931: Prevent warnings from -Wmissing-prototypes. - Fix to scrub resource records of type A and AAAA that have an inappropriate size. They are removed from responses. - Fix to move msgparse_rrset_remove_rr code to util/msgparse.c. - Fix to add EDE text when RRs have been removed due to length. - Fix to set ede match in unit test for rr length removal. - Fix to print EDE text in readable form in output logs. - Fix send of udp retries when ENOBUFS is returned. It stops looping and also waits for the condition to go away. Reported by Florian Obser. - Fix authority zone answers for obscured DNAMEs and delegations. - Merge #936: Check for c99 with autoconf versions prior to 2.70. - Fix to remove two c99 notations. - Fix rpz tcp-only action with rpz triggers nsdname and nsip. - Fix misplaced comment. - Merge #881: Generalise the proxy protocol code. - Fix #946: Forwarder returns servfail on upstream response noerror no data. - Fix edns subnet so that queries with a source prefix of zero cause the recursor send no edns subnet option to the upstream. - Fix that printout of EDNS options shows the EDNS cookie option by name. - Fix infinite loop when reading multiple lines of input on a broken remote control socket. Addesses #947 and #948. - Fix #949: "could not create control compt". - Fix that cachedb does not warn when serve-expired is disabled about use of serve-expired-reply-ttl and serve-expired-client-timeout. - Fix for #949: Fix pythonmod/ubmodule-tst.py for Python 3.x. - Better fix for infinite loop when reading multiple lines of input on a broken remote control socket, by treating a zero byte line the same as transmission end. Addesses #947 and #948. - For multi Python module setups, clean previously parsed module functions in __main__'s dictionary, if any, so that only current module functions are registered. - Fix #954: Inconsistent RPZ handling for A record returned along with CNAME. - Fixes for the DNS64 patches. - Update the dns64_lookup.rpl test for the DNS64 fallback patch. - Merge #955 from buevsan: fix ipset wrong behavior. - Update testdata/ipset.tdir test for ipset fix. - Fix to print detailed errors when an SSL IO routine fails via SSL_get_error. - Clearer configure text for missing protobuf-c development libraries. - autoconf. - Merge #930 from Stuart Henderson: add void to log_ident_revert_to_default declaration. - Fix #941: dnscrypt doesn't work after upgrade to 1.18 with suggestion by dukeartem to also fix the udp_ancil with dnscrypt. - Fix SSL compile failure for definition in log_crypto_err_io_code_arg. - Fix SSL compile failure for other missing definitions in log_crypto_err_io_code_arg. - Fix compilation without openssl, remove unused function warning. - Mention flex and bison in README.md when building from repository source.
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release-1.18.0
3795e374 · ·Unbound 1.18.0 This release adds DNS cookies downstream, support to respond with EDE error codes from cache, NAT64 support, and the capability to use a socket queue timeout to discard old packets, and other features and bug fixes. The downstream DNS server cookies are from RFC7873 and RFC9018, it is turned on with `answer-cookie: yes`. It generates a random cookie secret, but for anycast setups the cookie secret can be configured with `cookie-secret: "128bithex"` with the same value as the other instances. Non cookie traffic can be disallowed with the `allow_cookie` acl option for access-control. Queries with valid cookie bypass the ordinary ratelimit, but a ratelimit can be configured for cookie queries with `ip-ratelimit-cookie: 100`. The statistics has counters for `query_cookie_valid` and `query_cookie_client` and `query_cookie_invalid`. When queries come in with CD flag, a DNSSEC validation EDE can be returned, with information regarding a failure. EDE error information is also stored in the cache with the query responses. There is also EDE error information stored for the cachedb and the subnetcache. There is NAT64 support, that is enabled with `do-nat64: yes`. The NAT64 prefix can be configured too, if not the default `nat64-prefix: 64:ff9b::0/96`. This is useful for an IPv6 only host where Unbound is running, so that Unbound can use NAT64 to connect to IPv4 servers. The new default for the maximum UDP response size is 1232, with `max-udp-size: 1232`. This is similar to other resolvers. The new default is smaller and that makes it harder to get large responses. Thanks to Xiang Li, from NISL Lab, Tsinghua University. There is a new option `harden-unknown-additional: yes`. This removes unknown records from the authority and additional section. This stops unknown records from being copied from the upstream to the downstream client, potentially exposing those clients to the extra records. Default is no, because it could hamper future protocol developments that want to add records. Thanks to Xiang Li, from NISL Lab, Tsinghua University. With the `sock-queue-timeout: 3` option kernel timestamps are turned on for UDP queries, and old packets are dropped. Queries that have waited in the socket buffer for a long time are then discarded, and is useful if the host was not running for a while. The statistics has `num.queries_timed_out` and `query.queue_time_us.max` counters. The local-zone type `block_a` is for when queries to IPv4 have to be stopped to force IPv6 usage. It stops type A queries with nodata, and transparently allows other queries. The redis server can be contacted over a unix socket with `redis-server-path: "/var/lib/redis/redis-server.sock"`. The redis server password can be configured with `redis-server-password: "password"`. The number of hashtable collisions is logged in the statistics counters `msg.cache.max_collisions` and `rrset.cache.max_collisions`. It can be used to monitor for mistakes where the wrong or same hash value occurs too frequently. The repository does not have the bison and flex generated output in it, so these tools are necessary to compile from a checkout, the tarball distribution contains pregenerated files and can use either those files or bison and flex tools on the compile system. If kernel timestamps are enabled, with the sock-queue-timeout option, they are also used to set the time for dnstap logs. There is a yocto compatible init script available in the contrib directory of the source code, `unbound.init_yocto`. The number of cachedb hits from cache is output in `num.query.cachedb`. There is support for the dohpath parameter for the SVCB record type. Prefetch is supported for subnet cache entries. Detection of the python paths on the system has been expanded. Features - Merge #826: Аdd a metric about the maximum number of collisions in lrushah. - Set max-udp-size default to 1232. This is the same default value as the default value for edns-buffer-size. It restricts client edns buffer size choices, and makes unbound behave similar to other DNS resolvers. The new choice, down from 4096 means it is harder to get large responses from Unbound. Thanks to Xiang Li, from NISL Lab, Tsinghua University. - Add harden-unknown-additional option. It removes unknown records from the authority section and additional section. Thanks to Xiang Li, from NISL Lab, Tsinghua University. - Merge #819: Added new static zone type block_a to suppress all A queries for specific zones. - Fix #835: [FR] Ability to use Redis unix sockets. - Fix #833: [FR] Ability to set the Redis password. - Merge #882 from vvfedorenko: Features/dropqueuedpackets, with sock-queue-timeout option that drops packets that have been in the socket queue for too long. Added statistics num.queries_timed_out and query.queue_time_us.max that track the socket queue timeouts. - Merge #722 from David 'eqvinox' Lamparter: NAT64 support. - Fix #888: [FR] Use kernel timestamps for dnstap. - Merge #903: contrib: add yocto compatible init script. - Merge #892: Add cachedb hit stat. Introduces 'num.query.cachedb' as a new statistical counter. - Merge #739: Add SVCB dohpath support. - Merge #802: add validation EDEs to queries where the CD bit is set. - Merge #664 from tilan7763: Add prefetch support for subnet cache entries. - Merge #759 from Tom Carpay: Add EDE (RFC8914) caching. - Merge #790 from Tom Carpay: Add support for EDE caching in cachedb and subnetcache. - Merge PR #762: Downstream DNS Server Cookies a la RFC7873 and RFC9018. Create server cookies for clients that send client cookies. This needs to be explicitly turned on in the config file with: `answer-cookie: yes`. A `cookie-secret:` can be configured for anycast setups. Without one, a random cookie secret is generated. The acl option `allow_cookie` allows queries with either a valid cookie or over a stateful transport. The statistics output has `queries_cookie_valid` and `queries_cookie_client` and `queries_cookie_invalid` information. The `ip\-ratelimit\-cookie:` value determines a rate limit for queries with cookies, if desired. Bug Fixes - Fix #823: Response change to NODATA for some ANY queries since 1.12, tested on 1.16.1. - Fix python module install path detection. - Fix python version detection in configure. - Improve documentation for #826, describe the large collisions amount. - Fix not following cleared RD flags potentially enables amplification DDoS attacks, reported by Xiang Li and Wei Xu from NISL Lab, Tsinghua University. The fix stops query loops, by refusing to send RD=0 queries to a forwarder, they still get answered from cache. - Set default for harden-unknown-additional to no. So that it does not hamper future protocol developments. - Fix test for new default. - Fix acx_nlnetlabs.m4 for -Wstrict-prototypes. - Add duration variable for speed_local.test. - Fix #841: Unbound won't build with aaaa-filter-iterator.patch. - Fix to ignore entirely empty responses, and try at another authority. This turns completely empty responses, a type of noerror/nodata into a servfail, but they do not conform to RFC2308, and the retry can fetch improved content. - Fix unit tests for spurious empty messages. - Fix consistency of unit test without roundrobin answers for the cnametooptout unit test. - Fix to git ignore the library symbol file that configure can create. - Allow TTL refresh of expired error responses. - Add testcase for refreshing expired error responses. - Clean up iterator/iterator.c::error_response_cache() and allow for better interaction with serve-expired, prefetch and cached error responses. - Fix #825: Unexpected behavior with client-subnet-always-forward and serve-expired - Fix for #852: Completion of error handling. - Fix unbound-dnstap-socket test program to reply the finish frame over a TLS connection correctly. - Fix ssl.h include brackets, instead of quotes. - Fix #812, fix #846, by using the SSL_OP_IGNORE_UNEXPECTED_EOF option to ignore the unexpected eof while reading in openssl >= 3. - iana portlist update. - Fix issue #851: reserved identifier violation - Fix issue #676: Unencrypted query is sent when forward-tls-upstream: yes is used without tls-cert-bundle - Extra consistency check to make sure that when TLS is requested, either we set up a TLS connection or we return an error. - Fix #870: NXDOMAIN instead of NOERROR rcode when asked for existing CNAME record. - Fix for #870: Add test case for the qname minimisation and CNAME. - Fix build badge, from failing travis link to github ci action link. - Merge #875: change obsolete txt URL in unbound-anchor.c to point to RFC 7958, and Fix #874. - Fix for #878: Invalid IP address in unbound.conf causes Segmentation Fault on OpenBSD. - Fix for #882: small changes, date updated in Copyright for util/timeval_func.c and util/timeval_func.h. Man page entries and example entry. - Fix for #882: document variable to stop doxygen warning. - Fix issue #860: Bad interaction with 0 TTL records and serve-expired - Fix RPZ IP responses with trigger rpz-drop on cache entries, that they are dropped. - For #722: minor fixes, formatting, refactoring. - Fix #885: Error: util/configlexer.c: No such file or directory, adds error messages explaining to install flex and bison. - Fix to remove unused whitespace from acx_nlnetlabs.m4 and config.h. - Fix doxygen in addr_to_nat64 header definition. - Fix warning in windows compile, in set_recvtimestamp. - Fix to print debug log for ancillary data with correct IP address. - Fix RPZ removal of client-ip, nsip, nsdname triggers from IXFR. - Fix to remove unused variables from RPZ clientip data structure. - Fix unbound-dnstap-socket printout when no query is present. - Fix unbound-dnstap-socket time fraction conversion for printout. - Merge #896: Fix: #895: pythonmodule: add all site-packages directories to sys.path. - Fix #895: python + sysconfig gives ANOTHER path comparing to distutils. - Fix for uncertain unit test for doh buffer size events. - Properly handle all return values of worker_check_request during early EDE code. - Do not check the incoming request more than once. - Fix for issue #887 (Timeouts to forward servers on BSD based system with ASLR) - Probably fixes #516 (Stream reuse does not work on Windows) as well - Remove warning about unknown cast-function-type warning pragma. - Fix python modules with multiple scripts, by incrementing reference counts. - More fixes for reference counting for python module and clean up failure code. - Merge #827 from rcmcdonald91: Eliminate unnecessary Python reloading which causes memory leaks. - Fix #906: warning: ‘Py_SetProgramName’ is deprecated. - Fix dereference of NULL variable warning in mesh_do_callback. - Code cleanup for sldns_str2wire_svcparam_key_lookup. - For #802: Cleanup comments and add RCODE check for CD bit test case. - Skip the 00-lint test. splint is not maintained; it either does not work or produces false positives. Static analysis is handled in the clang test. - For #664: Easier code flow for subnetcache prefetching. - For #664: Add testcase. - For #664: Rename subnet_prefetch tests to subnet_global_prefetch to differentiate from the new subnet prefetch support. - Merge #880 from chipitsine: services/authzone.c: remove redundant check. - More clear description of the different auth-zone behaviors on the man page. - Merge #909 from headshog: Numeric truncation when parsing TYPEXX and CLASSXX representation. - For #909: Fix return values. - Merge #901 from Sergei Trofimovich: config: improve handling of unknown modules. - For #909: Fix RR class comparison. - Merge #857 from eaglegai: fix potential memory leaks when errors happen. - For #857: fix mixed declarations and code. - Merge #118 from mibere: Changed verbosity level for Redis init & deinit. - Merge #390 from Frank Riley: Add missing callbacks to the python module. - Cleaner failure code for callback functions in interface.i. - Merge #889 from borisVanhoof: Free memory in error case + remove unused function. - For #889: use netcat-openbsd instead of netcat-traditional. - For #889: Account for num_detached_states before possible mesh_state_delete when erroring out. - Fix unused variable compile warning for kernel timestamps in netevent.c - Merge #911 from natalie-reece: Exclude EDE before other EDNS options when there isn't enough space. - For #911: Try to trim EXTRA-TEXT (and LDNS_EDE_OTHER options altogether) before giving up on attaching EDE options. - More braces and formatting for Fix for EDNS EDE size calculation to avoid future bugs. - Fix to use the now cached EDE, if any, for CD_bit queries. - Fix for EDNS EDE size calculation. - Move a cache reply callback in worker.c closer to the cache reply generation. - Fix regional_alloc_init for potential unaligned source of the copy. - Fix ip_ratelimit test to work with dig that enables DNS cookies. - Fix for iter_dec_attempts that could cause a hang, part of capsforid and qname minimisation, depending on the settings. - Fix uninitialized memory passed in padding bytes of cmsg to sendmsg. - Fix stat_values test to work with dig that enables DNS cookies. - Debug Windows ci workflow. - Fix windows ci workflow to install bison and flex. - Fix for #925: unbound.service: Main process exited, code=killed, status=11/SEGV. Fixes cachedb configuration handling. - Fix #923: processQueryResponse() THROWAWAY should be mindful of fail_reply. - Fix unit test for unbound-control to work when threads are disabled, and fix cache dump check. - Fix compile error on NetBSD in util/netevent.h.
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