PT-2025-29837 · Nlnet+9 · Unbound+9
Xiang Li
·
Published
2025-07-16
·
Updated
2025-09-30
·
CVE-2025-5994
CVSS v4.0
8.7
High
| Vector | AV: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.
RCE
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Weakness Enumeration
Related Identifiers
Affected Products
Alt Linux
Almalinux
Centos
Debian
Linuxmint
Red Hat
Red Os
Rocky Linux
Ubuntu
Unbound