nlnetlabs CVE Vulnerabilities & Metrics

NLnet Labs Unbound up to and including version 1.21.0 contains a vulnerability when handling replies with very large RRsets that it needs to perform name compression for. Malicious upstreams responses with very large RRsets can cause Unbound to spend a considerable time applying name compression to downstream replies. This can lead to degraded performance and eventually denial of service in well orchestrated attacks. The vulnerability can be exploited by a malicious actor querying Unbound for the specially crafted contents of a malicious zone with very large RRsets. Before Unbound replies to the query it will try to apply name compression which was an unbounded operation that could lock the CPU until the whole packet was complete. Unbound version 1.21.1 introduces a hard limit on the number of name compression calculations it is willing to do per packet. Packets that need more compression will result in semi-compressed packets or truncated packets, even on TCP for huge messages, to avoid locking the CPU for long. This change should not affect normal DNS traffic.

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.

NLnet Labs’ Routinator 0.9.0 up to and including 0.12.1 contains a possible path traversal vulnerability in the optional, off-by-default keep-rrdp-responses feature that allows users to store the content of responses received for RRDP requests. The location of these stored responses is constructed from the URL of the request. Due to insufficient sanitation of the URL, it is possible for an attacker to craft a URL that results in the response being stored outside of the directory specified for it.

NLnet Labs' Routinator up to and including version 0.12.1 may crash when trying to parse certain malformed RPKI objects. This is due to insufficient input checking in the bcder library covered by CVE-2023-39914.

NLnet Labs' bcder library up to and including version 0.7.2 panics while decoding certain invalid input data rather than rejecting the data with an error. This can affect both the actual decoding stage as well as accessing content of types that utilized delayed decoding.

NLnet Labs Krill supports direct access to the RRDP repository content through its built-in web server at the "/rrdp" endpoint. Prior to 0.12.1 a direct query for any existing directory under "/rrdp/", rather than an RRDP file such as "/rrdp/notification.xml" as would be expected, causes Krill to crash. If the built-in "/rrdp" endpoint is exposed directly to the internet, then malicious remote parties can cause the publication server to crash. The repository content is not affected by this, but the availability of the server and repository can cause issues if this attack is persistent and is not mitigated.

A vulnerability named 'Non-Responsive Delegation Attack' (NRDelegation Attack) has been discovered in various DNS resolving software. The NRDelegation Attack works by having a malicious delegation with a considerable number of non responsive nameservers. The attack starts by querying a resolver for a record that relies on those unresponsive nameservers. The attack can cause a resolver to spend a lot of time/resources resolving records under a malicious delegation point where a considerable number of unresponsive NS records reside. It can trigger high CPU usage in some resolver implementations that continually look in the cache for resolved NS records in that delegation. This can lead to degraded performance and eventually denial of service in orchestrated attacks. Unbound does not suffer from high CPU usage, but resources are still needed for resolving the malicious delegation. Unbound will keep trying to resolve the record until hard limits are reached. Based on the nature of the attack and the replies, different limits could be reached. From version 1.16.3 on, Unbound introduces fixes for better performance when under load, by cutting opportunistic queries for nameserver discovery and DNSKEY prefetching and limiting the number of times a delegation point can issue a cache lookup for missing records.

In NLnet Labs Routinator 0.9.0 up to and including 0.11.2, due to a mistake in error handling, data in RRDP snapshot and delta files that isn’t correctly base 64 encoded is treated as a fatal error and causes Routinator to exit. Worst case impact of this vulnerability is denial of service for the RPKI data that Routinator provides to routers. This may stop your network from validating route origins based on RPKI data. This vulnerability does not allow an attacker to manipulate RPKI data.

NLnet Labs Unbound, up to and including version 1.16.1, is vulnerable to a novel type of the "ghost domain names" attack. The vulnerability works by targeting an Unbound instance. Unbound is queried for a rogue domain name when the cached delegation information is about to expire. The rogue nameserver delays the response so that the cached delegation information is expired. Upon receiving the delayed answer containing the delegation information, Unbound overwrites the now expired entries. This action can be repeated when the delegation information is about to expire making the rogue delegation information ever-updating. From version 1.16.2 on, Unbound stores the start time for a query and uses that to decide if the cached delegation information can be overwritten.

NLnet Labs Unbound, up to and including version 1.16.1 is vulnerable to a novel type of the "ghost domain names" attack. The vulnerability works by targeting an Unbound instance. Unbound is queried for a subdomain of a rogue domain name. The rogue nameserver returns delegation information for the subdomain that updates Unbound's delegation cache. This action can be repeated before expiry of the delegation information by querying Unbound for a second level subdomain which the rogue nameserver provides new delegation information. Since Unbound is a child-centric resolver, the ever-updating child delegation information can keep a rogue domain name resolvable long after revocation. From version 1.16.2 on, Unbound checks the validity of parent delegation records before using cached delegation information.

When a zone file in ldns 1.7.1 is parsed, the function ldns_nsec3_salt_data is too trusted for the length value obtained from the zone file. When the memcpy is copied, the 0xfe - ldns_rdf_size(salt_rdf) byte data can be copied, causing heap overflow information leakage.

When ldns version 1.7.1 verifies a zone file, the ldns_rr_new_frm_str_internal function has a heap out of bounds read vulnerability. An attacker can leak information on the heap by constructing a zone file payload.

NLnet Labs Routinator versions 0.9.0 up to and including 0.10.1, support the gzip transfer encoding when querying RRDP repositories. This encoding can be used by an RRDP repository to cause an out-of-memory crash in these versions of Routinator. RRDP uses XML which allows arbitrary amounts of white space in the encoded data. The gzip scheme compresses such white space extremely well, leading to very small compressed files that become huge when being decompressed for further processing, big enough that Routinator runs out of memory when parsing input data waiting for the next XML element.

In NLnet Labs Routinator prior to 0.10.2, a validation run can be delayed significantly by an RRDP repository by not answering but slowly drip-feeding bytes to keep the connection alive. This can be used to effectively stall validation. While Routinator has a configurable time-out value for RRDP connections, this time-out was only applied to individual read or write operations rather than the complete request. Thus, if an RRDP repository sends a little bit of data before that time-out expired, it can continuously extend the time it takes for the request to finish. Since validation will only continue once the update of an RRDP repository has concluded, this delay will cause validation to stall, leading to Routinator continuing to serve the old data set or, if in the initial validation run directly after starting, never serve any data at all.

NLnet Labs Routinator prior to 0.10.2 happily processes a chain of RRDP repositories of infinite length causing it to never finish a validation run. In RPKI, a CA can choose the RRDP repository it wishes to publish its data in. By continuously generating a new child CA that only consists of another CA using a different RRDP repository, a malicious CA can create a chain of CAs of de-facto infinite length. Routinator prior to version 0.10.2 did not contain a limit on the length of such a chain and will therefore continue to process this chain forever. As a result, the validation run will never finish, leading to Routinator continuing to serve the old data set or, if in the initial validation run directly after starting, never serve any data at all.

NLnet Labs Routinator prior to 0.10.0 produces invalid RTR payload if an RPKI CA uses too large values in the max-length parameter in a ROA. This will lead to RTR clients such as routers to reject the RPKI data set, effectively disabling Route Origin Validation.

Unbound before 1.9.5 allows an out-of-bounds write via a compressed name in rdata_copy. NOTE: The vendor disputes that this is a vulnerability. Although the code may be vulnerable, a running Unbound installation cannot be remotely or locally exploited

Unbound before 1.9.5 allows an assertion failure via a compressed name in dname_pkt_copy. NOTE: The vendor disputes that this is a vulnerability. Although the code may be vulnerable, a running Unbound installation cannot be remotely or locally exploited

Unbound before 1.9.5 allows an infinite loop via a compressed name in dname_pkt_copy. NOTE: The vendor disputes that this is a vulnerability. Although the code may be vulnerable, a running Unbound installation cannot be remotely or locally exploited

Unbound before 1.9.5 allows an integer overflow in a size calculation in respip/respip.c. NOTE: The vendor disputes that this is a vulnerability. Although the code may be vulnerable, a running Unbound installation cannot be remotely or locally exploited

Unbound before 1.9.5 allows an integer overflow in a size calculation in dnscrypt/dnscrypt.c. NOTE: The vendor disputes that this is a vulnerability. Although the code may be vulnerable, a running Unbound installation cannot be remotely or locally exploited

Unbound before 1.9.5 allows an assertion failure and denial of service in dname_pkt_copy via an invalid packet. NOTE: The vendor disputes that this is a vulnerability. Although the code may be vulnerable, a running Unbound installation cannot be remotely or locally exploited

Unbound before 1.9.5 allows an assertion failure and denial of service in synth_cname. NOTE: The vendor disputes that this is a vulnerability. Although the code may be vulnerable, a running Unbound installation cannot be remotely or locally exploited

Unbound before 1.9.5 allows an out-of-bounds write in sldns_bget_token_par. NOTE: The vendor disputes that this is a vulnerability. Although the code may be vulnerable, a running Unbound installation cannot be remotely or locally exploited

Unbound before 1.9.5 allows an integer overflow in sldns_str2wire_dname_buf_origin, leading to an out-of-bounds write. NOTE: The vendor disputes that this is a vulnerability. Although the code may be vulnerable, a running Unbound installation cannot be remotely or locally exploited

Unbound before 1.9.5 allows an integer overflow in the regional allocator via the ALIGN_UP macro. NOTE: The vendor disputes that this is a vulnerability. Although the code may be vulnerable, a running Unbound installation cannot be remotely or locally exploited

Unbound before 1.9.5 allows an integer overflow in the regional allocator via regional_alloc. NOTE: The vendor disputes that this is a vulnerability. Although the code may be vulnerable, a running Unbound installation cannot be remotely or locally exploited

Unbound before 1.9.5 allows configuration injection in create_unbound_ad_servers.sh upon a successful man-in-the-middle attack against a cleartext HTTP session. NOTE: The vendor does not consider this a vulnerability of the Unbound software. create_unbound_ad_servers.sh is a contributed script from the community that facilitates automatic configuration creation. It is not part of the Unbound installation

NLnet Labs Unbound, up to and including version 1.12.0, and NLnet Labs NSD, up to and including version 4.3.3, contain a local vulnerability that would allow for a local symlink attack. When writing the PID file, Unbound and NSD create the file if it is not there, or open an existing file for writing. In case the file was already present, they would follow symlinks if the file happened to be a symlink instead of a regular file. An additional chown of the file would then take place after it was written, making the user Unbound/NSD is supposed to run as the new owner of the file. If an attacker has local access to the user Unbound/NSD runs as, she could create a symlink in place of the PID file pointing to a file that she would like to erase. If then Unbound/NSD is killed and the PID file is not cleared, upon restarting with root privileges, Unbound/NSD will rewrite any file pointed at by the symlink. This is a local vulnerability that could create a Denial of Service of the system Unbound/NSD is running on. It requires an attacker having access to the limited permission user Unbound/NSD runs as and point through the symlink to a critical file on the system.

An incomplete fix for CVE-2020-12662 was shipped for Unbound in Red Hat Enterprise Linux 7, as part of erratum RHSA-2020:2414. Vulnerable versions of Unbound could still amplify an incoming query into a large number of queries directed to a target, even with a lower amplification ratio compared to versions of Unbound that shipped before the mentioned erratum. This issue is about the incomplete fix for CVE-2020-12662, and it does not affect upstream versions of Unbound.

An issue was discovered in NLnet Labs Routinator 0.1.0 through 0.7.1. It allows remote attackers to bypass intended access restrictions or to cause a denial of service on dependent routing systems by strategically withholding RPKI Route Origin Authorisation ".roa" files or X509 Certificate Revocation List files from the RPKI relying party's view.

Unbound before 1.10.1 has an infinite loop via malformed DNS answers received from upstream servers.

Unbound before 1.10.1 has Insufficient Control of Network Message Volume, aka an "NXNSAttack" issue. This is triggered by random subdomains in the NSDNAME in NS records.

Unbound 1.6.4 through 1.9.4 contain a vulnerability in the ipsec module that can cause shell code execution after receiving a specially crafted answer. This issue can only be triggered if unbound was compiled with `--enable-ipsecmod` support, and ipsecmod is enabled and used in the configuration.

Cache Poisoning issue exists in DNS Response Rate Limiting.

Unbound before 1.9.4 accesses uninitialized memory, which allows remote attackers to trigger a crash via a crafted NOTIFY query. The source IP address of the query must match an access-control rule.

nsd-checkzone in NLnet Labs NSD 4.2.0 has a Stack-based Buffer Overflow in the dname_concatenate() function in dname.c.

A flaw was found in the way unbound before 1.6.8 validated wildcard-synthesized NSEC records. An improperly validated wildcard NSEC record could be used to prove the non-existence (NXDOMAIN answer) of an existing wildcard record, or trick unbound into accepting a NODATA proof.

A double-free vulnerability in str2host.c in ldns 1.7.0 have unspecified impact and attack vectors.

A double-free vulnerability in parse.c in ldns 1.7.0 have unspecified impact and attack vectors.

NSD before 4.1.11 allows remote DNS master servers to cause a denial of service (/tmp disk consumption and slave server crash) via a zone transfer with unlimited data.

iterator.c in NLnet Labs Unbound before 1.5.1 does not limit delegation chaining, which allows remote attackers to cause a denial of service (memory and CPU consumption) via a large or infinite number of referrals.

The ldns-keygen tool in ldns 1.6.x uses the current umask to set the privileges of the private key, which might allow local users to obtain the private key by reading the file.

query.c in NSD 3.0.x through 3.0.8, 3.1.x through 3.1.1, and 3.2.x before 3.2.12 allows remote attackers to cause a denial of service (NULL pointer dereference and child process crash) via a crafted DNS packet.

Heap-based buffer overflow in the ldns_rr_new_frm_str_internal function in ldns before 1.6.11 allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a Resource Record (RR) with an unknown type containing input that is longer than a specified length.

Unbound before 1.4.4 does not send responses for signed zones after mishandling an unspecified query, which allows remote attackers to cause a denial of service (DNSSEC outage) via a crafted query.

daemon/worker.c in Unbound 1.x before 1.4.10, when debugging functionality and the interface-automatic option are enabled, allows remote attackers to cause a denial of service (assertion failure and daemon exit) via a crafted DNS request that triggers improper error handling.

Unbound before 1.4.3 does not properly align structures on 64-bit platforms, which allows remote attackers to cause a denial of service (daemon crash) via unspecified vectors.

Unbound before 1.3.4 does not properly verify signatures for NSEC3 records, which allows remote attackers to cause secure delegations to be downgraded via DNS spoofing or other DNS-related attacks in conjunction with crafted delegation responses.

Off-by-one error in the packet_read_query_section function in packet.c in nsd 3.2.1, and process_query_section in query.c in nsd 2.3.7, allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via unspecified vectors that trigger a buffer overflow.

Heap-based buffer overflow in the ldns_rr_new_frm_str_internal function in ldns 1.4.x allows remote attackers to cause a denial of service (memory corruption) and possibly execute arbitrary code via a DNS resource record (RR) with a long (1) class field (clas variable) and possibly (2) TTL field.