CVE-2025-24802highCWE-1240

Soundness issue with Plonky2 look up tables

21Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 8.6epss 0.3%

exploitation probability

0.3%top 76% of all CVEs

observed exploitation

nono source reports it

In short

Plonky2's lookup tables have a flaw where a dishonest prover can falsely prove that any function returns 0 when given 0 as input, unless the table size meets specific requirements. This breaks the security guarantee of proofs generated with affected lookup tables.

Technical detail

The vulnerability stems from zero-padding in LookupTableGate when table length is not divisible by 26 (floor(num_routed_wires / 3)), allowing a malicious prover to forge proofs for the f(0) = 0 input-output pair regardless of the actual lookup table contents. This soundness issue undermines the cryptographic integrity of PLONK-based SNARKs and is mitigated by padding tables to divisible lengths or upgrading to version 1.0.1.

Summary generated and translated by AI from the official description.

Plonky2 is a SNARK implementation based on techniques from PLONK and FRI. Lookup tables, whose length is not divisible by 26 = floor(num_routed_wires / 3) always include the 0 -> 0 input-output pair. Thus a malicious prover can always prove that f(0) = 0 for any lookup table f (unless its length happens to be divisible by 26). The cause of problem is that the LookupTableGate-s are padded with zeros. A workaround from the user side is to extend the table (by repeating some entries) so that its length becomes divisible by 26. This vulnerability is fixed in 1.0.1.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N

Affected products

0xPolygonZero · plonky2

References

https://github.com/0xPolygonZero/plonky2/blob/main/plonky2/src/plonk/prover.rs#L97 https://github.com/0xPolygonZero/plonky2/commit/091047f7f10cae082716f3738ad59a583835f7b6 https://github.com/0xPolygonZero/plonky2/security/advisories/GHSA-hj49-h7fq-px5h