Updated: 2026-02-27 03:42:56.769809
Description:
The Closest Encloser Proof aspect of the DNS protocol (in RFC 5155 when RFC 9276 guidance is skipped) allows remote attackers to cause a denial of service (CPU consumption for SHA-1 computations) via DNSSEC responses in a random subdomain attack, aka the "NSEC3" issue. The RFC 5155 specification implies that an algorithm must perform thousands of iterations of a hash function in certain situations.
| Links | NIST | CIRCL | RHEL | Ubuntu |
| Severity | Score | |
|---|---|---|
| CVSS Version 2.x | 0.0 | |
| CVSS Version 3.x | HIGH | 7.5 |
| OS name | Project name | Version | Score | Severity | Status | Errata | Last updated | Statement |
|---|---|---|---|---|---|---|---|---|
| RHEL 7 ELS | dhcp | 4.2.5 | 7.5 | HIGH | Already Fixed | 2025-08-20 07:18:09 | ||
| RHEL 7 ELS | bind | 9.11.4 | 7.5 | HIGH | Released | CLSA-2025:1755512368 | 2025-08-19 06:33:22 | |
| TuxCare 9.6 ESU | unbound | 1.16.2 | 7.5 | HIGH | Already Fixed | 2025-12-08 17:13:06 | ||
| Ubuntu 16.04 ELS | bind9 | 9.10.3 | 7.5 | HIGH | Released | CLSA-2024:1709562163 | 2024-03-04 10:08:45 | |
| Ubuntu 16.04 ELS | dhcp | 4.3.3 | 7.5 | HIGH | Not Vulnerable | 2024-10-09 14:26:49 | ||
| Ubuntu 18.04 ELS | bind9 | 9.11.3 | 7.5 | HIGH | Released | CLSA-2024:1709562964 | 2024-03-04 10:08:43 | |
| Ubuntu 18.04 ELS | dhcp | 4.3.5 | 7.5 | HIGH | Not Vulnerable | 2024-10-09 14:26:52 |