CVE-2025-40776
Description
A flaw was found in the named caching resolver, a component of BIND 9. When this resolver is configured to send EDNS Client Subnet (ECS) options, it may be vulnerable to a cache-poisoning attack. A remote attacker could exploit this to compromise the integrity of cached DNS data. This could lead to users being redirected to malicious websites or services. EDNS Client Subnet (ECS) options are only available in the BIND Subscription Edition (-S), so only the -S edition is affected by this CVE.
Statement
Red Hat does not ship the BIND Subscription Edition.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 8.6 | N/A | N/A |
| Attack Vector | Network | N/A | N/A |
| Attack Complexity | Low | N/A | N/A |
| Privileges Required | None | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Changed | N/A | N/A |
| Confidentiality | None | N/A | N/A |
| Integrity Impact | High | N/A | N/A |
| Availability Impact | None | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N
Understanding the Weakness (CWE)
Access Control,Integrity
Technical Impact: Bypass Protection Mechanism; Modify Application Data
An attacker could package untrusted data with trusted data to bypass protection mechanisms to gain access to and possibly modify sensitive data.
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