Summary
tss-lib leaks secret keys in response to incorrectly constructed Paillier moduli
References
Impact
The specification of the GG18 threshold ECDSA signature protocol contains a vulnerability allowing an attacker to recover the shared secret key. If a participant generates a Paillier modulus N containing small factors (less than 2^100) they can interact with other participants in the signing protocol to steal their secret key shares in as little as sixteen signing attempts. The master key can then be reconstructed from these shares.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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The implementation of GG18 in tss-lib did not prove that N is biprime or that it doesn't contain small factors. The fixed implementation adds the following proofs from the CGGMP21 threshold ECDSA protocol to the key generation:
- Paillier-Blum Modulus (
Nis the product of two primes) - No Small Factor (both factors of
Nare greater than2^256)
These proofs apply to both the Paillier encryption modulus N, and the modulus NTilde used in MTA proofs.
To address the issue in the resharing protocol, an additional round has been added to the end so that participants can confirm that they received valid proofs.
Frequently Asked Questions
- What is GHSA-H24C-6P6P-M3VX? GHSA-H24C-6P6P-M3VX is a critical-severity security vulnerability in github.com/bnb-chain/tss-lib (go), affecting versions <= 1.3.5. No fixed version is listed yet.
- Which versions of github.com/bnb-chain/tss-lib are affected by GHSA-H24C-6P6P-M3VX? github.com/bnb-chain/tss-lib (go) versions <= 1.3.5 is affected.
- Is there a fix for GHSA-H24C-6P6P-M3VX? No fixed version is listed for GHSA-H24C-6P6P-M3VX yet. Monitor the advisory for updates and apply mitigations in the interim.
- Is GHSA-H24C-6P6P-M3VX exploitable, and should I be worried? Whether GHSA-H24C-6P6P-M3VX is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether GHSA-H24C-6P6P-M3VX is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.