Unauthenticated DNS cache poisoning via unvalidated responses
Published Apr 7, 2026 · Updated Apr 7, 2026
DNS cache poisoning in Dual DHCP DNS Server 8.01 and earlier allows remote attackers to redirect clients via forged UDP responses. The forwarder reuses the client-supplied TXID, indexes pending requests by that value, and unconditionally caches matching responses without validating their source address or bailiwick. An off-path attacker must inject a forged response before the legitimate upstream reply; success redirects subsequent lookups for the poisoned name to an attacker-selected address.
Summary
What happened
DNS cache poisoning in Dual DHCP DNS Server 8.01 and earlier allows remote attackers to redirect clients via forged UDP responses. The forwarder reuses the client-supplied TXID, indexes pending requests by that value, and unconditionally caches matching responses without validating their source address or bailiwick. An off-path attacker must inject a forged response before the legitimate upstream reply; success redirects subsequent lookups for the poisoned name to an attacker-selected address.
The record
- CVE
- CVE-2025-71058
- Published
- Apr 7, 2026
- Updated
- Apr 7, 2026
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- T1557
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 7, 2026CVE publishedPublication date reported by the CVE source.
- Apr 7, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
What conditions does exploitation require?
What is affected?
Affected products and versions are unavailable in this record.
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Two-phase DNS cache poisoning proof of conceptfunctional · unverified
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Technologies
Your stack
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Your stack
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