PT-2025-29837
CVE-2025-5994
·
Published
2025-07-16
·
Updated
2026-10-24
Description by
CVSS 4.0
8.7
HighMetricsAV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:U/V:C/RE:X/U:X
Name of the Vulnerable Software and Affected Versions
Unbound (affected versions not specified)
Description
A multi-vendor cache poisoning vulnerability, named 'Rebirthday Attack', has been discovered in caching resolvers that support EDNS Client Subnet (ECS). Unbound is vulnerable when compiled with ECS support (i.e., '--enable-subnet') and configured to send ECS information 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). This allows malicious actors to potentially match DNS transaction IDs and cache poisonous replies.
Recommendations
At the moment, there is no information about a newer version that contains a fix for this vulnerability.
Found an issue in the description? Have something to add? Feel free to write us 👾