Detections
Analytics

Alpine: multiple unbound packages, py-unbound: security update to 1.23.1-r0

high Tenable Cloud Security Plugin ID 428457

Description

There are packages installed that are affected by a vulnerability referenced in the following CVE:

 - A multi-vendor cache poisoning vulnerability named 'Rebirthday Attack' has been discovered in caching
 resolvers that support EDNS Client Subnet (ECS). Unbound is also vulnerable when compiled with ECS
 support, i.e., '--enable-subnet', AND configured to send ECS information along with queries to upstream
 name servers, i.e., at least one of the 'send-client-subnet', 'client-subnet-zone' or 'client-subnet-
 always-forward' options is used. Resolvers supporting ECS need to segregate outgoing queries to
 accommodate for different outgoing ECS information. This re-opens up resolvers to a birthday paradox
 attack (Rebirthday Attack) that tries to match the DNS transaction ID in order to cache non-ECS poisonous
 replies. (CVE-2025-5994)

See Also

https://security.alpinelinux.org/vuln/CVE-2025-5994

Plugin Details

Severity: High

ID: 428457

Version: Revision 1.9

Type: Local

Published: 7/19/2025

Updated: 7/2/2026

Supported Sensors: Agentless Assessment, Tenable Cloud Security, Tenable Self-Hosted Container Security

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.18

CVSS v2

Risk Factor: Medium

Base Score: 5.8

Temporal Score: 4.3

Vector: CVSS2#AV:N/AC:M/Au:N/C:P/I:P/A:N

CVSS Score Source: CVE-2025-5994

CVSS v3

Risk Factor: Critical

Base Score: 9.1

Temporal Score: 7.9

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

CVSS v4

Risk Factor: High

Base Score: 8.7

Threat Score: 6.6

Threat Vector: CVSS:4.0/E:U

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

Vulnerability Information

Exploit Ease: No known exploits are available

Vulnerability Publication Date: 7/16/2025

Reference Information

CVE: CVE-2025-5994