Description (CNA)
In NLnet Labs Unbound 1.18.0 up to and including 1.25.1, when Unbound listens on a 'proxy-protocol-port' interface with 'answer-cookie: yes', the RFC 9018 server-cookie SipHash is computed over the proxy's wire address instead of the PROXYv2-declared client. One server cookie obtained through a given proxy node therefore validates for every PROXYv2-declared source behind that node. On a UDP+proxy-protocol front, an off-path attacker can harvest one cookie with a single legitimate query, then replay it under any spoofed source and pass DNS Cookie checks that were deployed to defeat this in the first place.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| NLnet Labs / Unbound | affected 1.18.0 before 1.25.2 |
CWE
CWE-290
References
ADP enrichment
No English description supplied.
No references supplied.