GHSA-3v94-mw7p-v465
ADVISORY - githubSummary
The NSEC3 closest-encloser proof validation in hickory-proto's (0.25.0-alpha.3 ... 0.25.2) and hickory-net's (0.26.0-alpha.1 .. 0.26.0) DnssecDnsHandle walks from the QNAME up to the SOA owner name, building a list of candidate encloser names. The iterator used assumes the QNAME is a descendant of the SOA owner, terminating only when the current candidate equals the SOA name. When the SOA in a response's authority section is not an ancestor of the QNAME, the loop stalls at the DNS root and never terminates, repeatedly calling Name::base_name() and pushing newly allocated Name and hashed-name entries into the candidate Vec.
The bug is reachable by any caller of DnssecDnsHandle, including the resolver, recursor, and client, when built with the dnssec-ring or dnssec-aws-lc-rs feature and configured to perform DNSSEC validation. It is triggered while validating a NoData or NXDomain response whose authority section contains an SOA record from a zone other than an ancestor of the QNAME, on a code path that requires NSEC3 closest-encloser proof. In practice this can be reached through an insecure CNAME chain that crosses zone boundaries into a DNSSEC-signed zone returning NoData, but the minimum condition is just a mismatched SOA owner on a response requiring NSEC3 validation.
A debug_assert_ne!(name, Name::root()) guards the loop body, so debug builds abort with a panic on the first iteration past the root. Release builds compile the assertion out and run the loop unbounded, allocating until the process exhausts available memory. A reachable upstream attacker who can return such a response can therefore crash a debug build or exhaust memory on a release build, for the affected configurations.
The affected code was migrated from hickory-proto to hickory-net as part of the 0.26.0 release. Hickory DNS recommends that all affected users update to hickory-net 0.26.1 for the fix.
Reporter
David Cook, ISRG
Common Weakness Enumeration (CWE)
Loop with Unreachable Exit Condition ('Infinite Loop')
GitHub
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CVSS SCORE
8.7high| Package | Type | OS Name | OS Version | Affected Ranges | Fix Versions |
|---|---|---|---|---|---|
| hickory-proto | cargo | - | - | >=0.25.0-alpha.3,<=0.25.2 | Not yet available |
| hickory-net | cargo | - | - | >=0.26.0-alpha.1,<=0.26.0 | 0.26.1 |
CVSS:4 Severity and metrics
The CVSS metrics represent different qualitative aspects of a vulnerability that impact the overall score, as defined by the CVSS Specification.
The vulnerable component is bound to the network stack, but the attack is limited at the protocol level to a logically adjacent topology. This can mean an attack must be launched from the same shared physical (e.g., Bluetooth or IEEE 802.11) or logical (e.g., local IP subnet) network, or from within a secure or otherwise limited administrative domain (e.g., MPLS, secure VPN to an administrative network zone). One example of an Adjacent attack would be an ARP (IPv4) or neighbor discovery (IPv6) flood leading to a denial of service on the local LAN segment (e.g., CVE-2013-6014).
Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success when attacking the vulnerable component.
The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
The attacker is unauthenticated prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
The vulnerable system can be exploited without interaction from any human user, other than the attacker. Examples include: a remote attacker is able to send packets to a target system a locally authenticated attacker executes code to elevate privileges.
There is no loss of confidentiality within the Vulnerable System.
There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
There is no loss of integrity within the Vulnerable System.
There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
There is a total loss of availability, resulting in the attacker being able to fully deny access to resources in the Vulnerable System; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the Vulnerable System (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).
There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.
RustSec
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RustSec
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