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Vulnerability DatabaseCVE-2021-40083
CVE-2021-40083:
Linux Debian vulnerability analysis and mitigation
Overview
CVE-2021-40083 affects Knot Resolver versions before 5.3.2. The vulnerability was discovered in August 2021 and involves an assertion failure that can be triggered by a remote attacker in a specific edge case involving NSEC3 with excessive iterations used for a positive wildcard proof (NVD).
Technical details
The vulnerability is classified with a CVSS v3.1 Base Score of 7.5 (HIGH) with the vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. The issue specifically relates to an assertion failure in the validator component when handling NSEC3 records with excessive iterations used for positive wildcard proofs (NVD).
Impact
When exploited, the vulnerability can lead to a denial of service condition through assertion failure, affecting the availability of the DNS resolver service (NVD).
Mitigation and workarounds
The vulnerability has been fixed in Knot Resolver version 5.3.2. Users are advised to upgrade to this version or later to mitigate the issue. The fix involves modifications to the validator component to properly handle NSEC3 records with excessive iterations (Knot MR).
Additional resources
Source: This report was generated using AI
Related Linux Debian vulnerabilities:
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