CyberSecBulletin
CVE-2025-66017NVD status: Deferred

cggmp21: Use of a Broken or Risky Cryptographic Algorithm

CVE-2025-66017 is a high-severity use of a broken or risky cryptographic algorithm vulnerability in cggmp21 from LFDT-Lockness, with a CVSS 4.0 base score of 8.2 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected cggmp21 versions: cggmp21 <= 0.6.3; cggmp24 = 0.7.0-alpha.1. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.22% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of cggmp21 you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
LFDT-Locknesscggmp21cggmp21 <= 0.6.3; cggmp24 = 0.7.0-alpha.1Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Attack requirements
PresentThe target must be in a specific state or configuration for the attack to work.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Confidentiality (vulnerable system)
NoneNo loss of confidentiality on the vulnerable system.
Integrity (vulnerable system)
HighSerious loss of integrity on the vulnerable system.
Availability (vulnerable system)
NoneNo loss of availability on the vulnerable system.
Confidentiality (other systems)
NoneNo loss of confidentiality on systems beyond the vulnerable one.
Integrity (other systems)
NoneNo loss of integrity on systems beyond the vulnerable one.
Availability (other systems)
NoneNo loss of availability on systems beyond the vulnerable one.

Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. Scored by CNA (github.com).

Official description

CGGMP24 is a state-of-art ECDSA TSS protocol that supports 1-round signing (requires 3 preprocessing rounds), identifiable abort, and a key refresh protocol. In versions 0.6.3 and prior of cggmp21 and version 0.7.0-alpha.1 of cggmp24, presignatures can be used in the way that significantly reduces security. cggmp24 version 0.7.0-alpha.2 release contains API changes that make it impossible to use presignatures in contexts in which it reduces security.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Use of a Broken or Risky Cryptographic Algorithm

The product uses a broken or risky cryptographic algorithm or protocol.

How developers prevent this class of flaw

  • Ensure that the design allows one cryptographic algorithm to be replaced with another in the next generation or version. Where possible, use wrappers to make the interfaces uniform. This will make it easier to upgrade to stronger algorithms. With hardware, design the product at the Intellectual Property (IP) level so that one cryptographic algorithm can be replaced with another in the next generation of the hardware product.
  • Carefully manage and protect cryptographic keys (see CWE-320). If the keys can be guessed or stolen, then the strength of the cryptography itself is irrelevant.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Industry-standard implementations will save development time and may be more likely to avoid errors that can occur during implementation of cryptographic algorithms. Consider the ESAPI Encryption feature.

More Use of a Broken or Risky Cryptographic Algorithm vulnerabilities (CWE-327)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in cggmp21

All cggmp21 vulnerabilities

Recent Use of a Broken or Risky Cryptographic Algorithm vulnerabilities

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