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The vulnerability exists within the go-f3 library’s message validation logic. When processing a specifically crafted malicious “poison” F3 message, the node fails to properly check for integer overflows during the validation of the signer index. An attacker can construct a message containing a large number of signers, triggering an integer overflow when the justification power is calculated. This integer overflow bypasses the intended validation checks, leading the code to access an invalid index in a data structure. The subsequent out-of-bounds access causes a critical runtime panic in the go-f3 library. In the context of the Lotus node implementation, this panic is unrecovered, resulting in the immediate and complete crash of the entire node process. The attack requires no special privileges or network power, making it highly accessible. However, exploitation is not self-propagating; the attacker must directly transmit the poison message to each target node.
Platform: Filecoin (Lotus/Forest/Venus)
Version: Pre nv27 upgrade
Vulnerability : Integer Overflow
Severity: Critical
date: 2024
Prediction: Patched in nv27
What Undercode Say:
git clone https://github.com/filecoin-project/go-f3 cd go-f3 git checkout v0.8.6 grep -r "justificationPower"
// Hypothetical vulnerable code snippet
func validateJustification(signers []int) error {
totalPower := 0
for _, signerIndex := range signers {
totalPower += powerTable[bash] // Potential overflow here
}
// ... validation logic
}
How Exploit:
Craft malicious F3 message.
Send message directly.
Trigger index overflow.
Cause node panic.
Protection from this CVE
Upgrade to go-f3 v0.8.7.
Apply nv27 upgrade.
No workarounds available.
Impact:
Full node crash.
Denial of service.
No attacker power required.
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Sources:
Reported By: github.com
Extra Source Hub:
Undercode
