Zebra before 6.4.0 Gossiped Block Drop via Forged Coinbase scriptSig Height
Impact
Zebra before 6.4.0 contains an improper integrity validation vulnerability in the inbound gossip download path that allows unauthenticated peers to force dropping of new blocks without penalty. Attackers can serve a real block with a coinbase scriptSig rewritten to height 1, which keeps the ZIP-244 block hash, triggering a behind-tip drop before consensus validation and delaying tip discovery for mining backends.
Source excerpt · VulnCheckAffected packages
Affected products
Vendor version evidence. Product records are separate from automatic dependency matching.
ZcashFoundation · zebra
Other versions: unaffected
| Version / range | Source status |
|---|---|
| 0 to before 6.4.0 | affected |
| 6.4.0 | unaffected |
Original source description
Zebra before 6.4.0 contains an improper integrity validation vulnerability in the inbound gossip download path that allows unauthenticated peers to force dropping of new blocks without penalty. Attackers can serve a real block with a coinbase scriptSig rewritten to height 1, which keeps the ZIP-244 block hash, triggering a behind-tip drop before consensus validation and delaying tip discovery for mining backends.