CVE-2025-29779 Post-Quantum Secure Feldman's Verifiable Secret Sharing has Inadequate Fault Injection Countermeasures in `secure_redundant_execution`
Inadequate fault injection countermeasures allow attackers with physical access to bypass security checks, extract secret coefficients, or accept invalid shares in the VSS scheme.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2025-29779?
CVE-2025-29779 is a medium-severity vulnerability in DavidOsipov PostQuantum-Feldman-VSS, published on 14 Mar 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
Post-Quantum Secure Feldman's Verifiable Secret Sharing provides a Python implementation of Feldman's Verifiable Secret Sharing (VSS) scheme. In versions 0.8.0b2 and prior, the `secure_redundant_execution` function in feldman_vss.py attempts to mitigate fault injection attacks by executing a function multiple times and comparing results. However, several critical weaknesses exist. Python's execution environment cannot guarantee true isolation between redundant executions, the constant-time comparison implementation in Python is subject to timing variations, the randomized execution order and timing provide insufficient protection against sophisticated fault attacks, and the error handling may leak timing information about partial execution results. These limitations make the protection ineffective against targeted fault injection attacks, especially from attackers with physical access to the hardware. A successful fault injection attack could allow an attacker to bypass the redundancy check mechanisms, extract secret polynomial coefficients during share generation or verification, force the acceptance of invalid shares during verification, and/or manipulate the commitment verification process to accept fraudulent commitments. This undermines the core security guarantees of the Verifiable Secret Sharing scheme. As of time of publication, no patched versions of Post-Quantum Secure Feldman's Verifiable Secret Sharing exist, but other mitigations are available. Long-term remediation requires reimplementing the security-critical functions in a lower-level language like Rust. Short-term mitigations include deploying the software in environments with physical security controls, increasing the redundancy count (from 5 to a higher number) by modifying the source code, adding external verification of cryptographic operations when possible, considering using hardware security modules (HSMs) for key operations.
Which versions are affected by CVE-2025-29779?
2 open source packages ship an affected version, including PostQuantum-Feldman-VSS and postquantum-feldman-vss.
| Package | Affected | Fixed in |
|---|---|---|
PostQuantum-Feldman-VSS PyPI | All versions to 0.8.0b2 | None |
postquantum-feldman-vss PyPI | All versions to 0.8.0b2 | None |
How do I fix CVE-2025-29779?
No fix has been published for CVE-2025-29779 yet. Limit exposure of the affected software until one is available.
Is CVE-2025-29779 being exploited?
There is no known exploitation of CVE-2025-29779 in the wild and no public exploit code.
Sources
Also known as GHSA-r8gc-qc2c-c7vh.