ResearchACM CCS 2025

RebirthDay Attack: Reviving DNS Cache Poisoning with the Birthday Paradox

Xiang Li, Mingming Zhang, Zuyao Xu et al.

Revisiting DNS cache poisoning through the birthday paradox.

Birthday attack mitigation and the RebirthDay threat model (Figures 4–5). Source ↗

Research question

Can the classic DNS birthday attack become practical again despite query aggregation? RebirthDay investigates how protocol-compliant DNS extension behavior can undermine this mitigation.

The mechanism

The work examines missing or inconsistent coherence checks for EDNS Client Subnet options. These weaknesses can let related queries bypass aggregation and revive the collision opportunities behind birthday-style cache poisoning.

Software ecosystem

The paper evaluates mainstream DNS implementations and reports coordinated findings to affected vendors. Its contribution connects protocol-extension handling with practical cache-poisoning defenses.

More figures

Threat model of the RebirthDay attack. Figure 5, page 6. Source ↗

DNS birthday attack and its mitigation. Figure 4, page 5. Source ↗

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