CVE-2025-29779: PostQuantum Feldman VSS Post-Quantum Secure Feldman's Verifiable Secret Vulnerability

MODERATE
Advisory Identifier: GHSA-r8gc-qc2c-c7vh
CWE-1240
Published
Advisory Summary

CVE-2025-29779 is a MODERATE post-quantum secure feldman's verifiable secret vulnerability (CWE-1240: Use of a Cryptographic Primitive with a Risky Implementation) affecting PostQuantum Feldman VSS libraries in the PyPI ecosystem. The issue involves post-quantum secure feldman's verifiable secret sharing has inadequate fault injection countermeasures in `secure_redundant_execution`. Remediation is available in the latest vendor maintenance releases.

CVE-2025-29779 at a Glance

CVE Identifier CVE-2025-29779
GHSA Identifier GHSA-r8gc-qc2c-c7vh
Severity MODERATE
CVSS v3.1 Base Score N/A
CWE Classification CWE-1240: Use of a Cryptographic Primitive with a Risky Implementation
Affected Product PostQuantum Feldman VSS
Package Ecosystem PyPI
Published Date
Last Updated

How to Fix CVE-2025-29779

To remediate this vulnerability, upgrade all affected PostQuantum Feldman VSS dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

PostQuantum-Feldman-VSS fixed: Latest secure release
pip install PostQuantum-Feldman-VSS>=Latest secure release
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

pip show PostQuantum-Feldman-VSS

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2025-29779, inspect your installed packages using pip:

pip show PostQuantum-Feldman-VSS

Analyze the terminal output to locate any version of PostQuantum Feldman VSS in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: The pip show PostQuantum-Feldman-VSS command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-1240: Use of a Cryptographic Primitive with a Risky Implementation, where to fulfill the need for a cryptographic primitive, the product implements a cryptographic algorithm using a non-standard, unproven, or disallowed/non-compliant cryptographic implementation. In PostQuantum Feldman VSS, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

**Description:** 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: 1. Python's execution environment cannot guarantee true isolation between redundant executions 2. The constant-time comparison implementation in Python is subject to timing variations 3. The randomized execution order and timing provide insufficient protection against sophisticated fault attacks 4. 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. **Impact:** A successful fault injection attack could allow an attacker to: 1. Bypass the redundancy check mechanisms 2. Extract secret polynomial coefficients during share generation or verification 3. Force the acceptance of invalid shares during verification 4. Manipulate the commitment verification process to accept fraudulent commitments This undermines the core security guarantees of the Verifiable Secret Sharing scheme. **References:** * File: `feldman_vss.py` * Function: `secure_redundant_execution` * [Fault Attacks](https://en.wikipedia.org/wiki/Fault_attack) - Wikipedia article on fault attacks. * Bar-El, H., et al. "The Sorcerer's Apprentice Guide to Fault Attacks" - https://eprint.iacr.org/2004/100.pdf * CWE-1279: https://cwe.mitre.org/data/definitions/1279.html * NIST SP 800-90B section on implementation validation **Remediation:** Long-term remediation requires reimplementing the security-critical functions in a lower-level language like Rust. Short-term mitigations: 1. Deploy the software in environments with physical security controls 2. Increase the redundancy count (from 5 to a higher number) by modifying the source code 3. Add external verification of cryptographic operations when possible 4. Consider using hardware security modules (HSMs) for key operations

CVE-2025-29779 Affected PostQuantum Feldman VSS Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
PostQuantum-Feldman-VSS
PyPI
≤ 0.8.0b2

References

Frequently Asked Questions

What is CVE-2025-29779?
CVE-2025-29779 is a security vulnerability in PostQuantum Feldman VSS involving Post-Quantum Secure Feldman's Verifiable Secret Sharing has Inadequate Fault Injection Countermeasures in `secure_redundant_execution` under CWE-1240: Use of a Cryptographic Primitive with a Risky Implementation.
Which PostQuantum Feldman VSS versions are affected?
Affected versions include releases prior to current release patches across affected packages: PostQuantum-Feldman-VSS.
What version fixes CVE-2025-29779?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is PostQuantum-Feldman-VSS affected?
Yes, PostQuantum-Feldman-VSS is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What CWE is associated with CVE-2025-29779?
CVE-2025-29779 is classified under CWE-1240: Use of a Cryptographic Primitive with a Risky Implementation (To fulfill the need for a cryptographic primitive, the product implements a cryptographic algorithm using a non-standard, unproven, or disallowed/non-compliant cryptographic implementation.).
How can I check PyPI dependencies for CVE-2025-29779?
Run the dependency tree command: 'pip show PostQuantum-Feldman-VSS'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-r8gc-qc2c-c7vh",
  "modified" : "2025-03-19T15:26:34Z",
  "published" : "2025-03-14T19:55:17Z",
  "aliases" : [ "CVE-2025-29779" ],
  "summary" : "Post-Quantum Secure Feldman's Verifiable Secret Sharing has Inadequate Fault Injection Countermeasures in `secure_redundant_execution`",
  "details" : "**Description:**\n\nThe `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:\n\n1. Python's execution environment cannot guarantee true isolation between redundant executions\n2. The constant-time comparison implementation in Python is subject to timing variations\n3. The randomized execution order and timing provide insufficient protection against sophisticated fault attacks\n4. The error handling may leak timing information about partial execution results\n\nThese limitations make the protection ineffective against targeted fault injection attacks, especially from attackers with physical access to the hardware.\n\n**Impact:**\n\nA successful fault injection attack could allow an attacker to:\n\n1. Bypass the redundancy check mechanisms\n2. Extract secret polynomial coefficients during share generation or verification\n3. Force the acceptance of invalid shares during verification\n4. Manipulate the commitment verification process to accept fraudulent commitments\n\nThis undermines the core security guarantees of the Verifiable Secret Sharing scheme.\n\n**References:**\n\n*   File: `feldman_vss.py`\n*   Function: `secure_redundant_execution`\n*   [Fault Attacks](https://en.wikipedia.org/wiki/Fault_attack) - Wikipedia article on fault attacks.\n*   Bar-El, H., et al. \"The Sorcerer's Apprentice Guide to Fault Attacks\" - https://eprint.iacr.org/2004/100.pdf\n* CWE-1279: https://cwe.mitre.org/data/definitions/1279.html\n* NIST SP 800-90B section on implementation validation\n\n\n**Remediation:**\n\nLong-term remediation requires reimplementing the security-critical functions in a lower-level language like Rust.\n\nShort-term mitigations:\n\n1. Deploy the software in environments with physical security controls\n2. Increase the redundancy count (from 5 to a higher number) by modifying the source code\n3. Add external verification of cryptographic operations when possible\n4. Consider using hardware security modules (HSMs) for key operations",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:P/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "PostQuantum-Feldman-VSS"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "0.8.0b2"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/DavidOsipov/PostQuantum-Feldman-VSS/security/advisories/GHSA-r8gc-qc2c-c7vh"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-29779"
  }, {
    "type" : "WEB",
    "url" : "https://en.wikipedia.org/wiki/Fault_attack"
  }, {
    "type" : "WEB",
    "url" : "https://eprint.iacr.org/2004/100.pdf"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/DavidOsipov/PostQuantum-Feldman-VSS"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-1240" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-03-14T19:55:17Z",
    "nvd_published_at" : "2025-03-14T18:15:32Z"
  }
}