CyberSecBulletin
CVE-2025-65951NVD status: Deferred

entropy-derby: Exposure of Sensitive Information to an Unauthorized Actor

CVE-2025-65951 is a high-severity exposure of sensitive information to an unauthorized actor vulnerability in entropy-derby from Mescuwa, with a CVSS 3.1 base score of 8.7 out of 10. It can be exploited remotely over the network by an attacker with administrator privileges, without any action from a user. Affected entropy-derby versions: < 2d38d2f16bbb3b4240698148f80d8c5202725c77. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.13% 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 entropy-derby 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.

Affected products and versions

VendorProductAffected versionsFixed in
Mescuwaentropy-derby< 2d38d2f16bbb3b4240698148f80d8c5202725c77Not 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.
Privileges required
HighAdministrator-level access is required first.
User interaction
NoneNo action by a victim is required.
Scope
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N. Scored by CNA (github.com).

Official description

Inside Track / Entropy Derby is a research-grade horse-racing betting engine. Prior to commit 2d38d2f, the VDF-based timelock encryption system fails to enforce sequential delay against the betting operator. Bettors pre-compute the entire Wesolowski VDF and include vdfOutputHex in their encrypted bet ticket, allowing the house to decrypt immediately using fast proof verification instead of expensive VDF evaluation. This issue has been patched via commit 2d38d2f.

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

The underlying weakness: Exposure of Sensitive Information to an Unauthorized Actor

The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.

How developers prevent this class of flaw

  • Compartmentalize the system to have safe areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.

More Exposure of Sensitive Information to an Unauthorized Actor vulnerabilities (CWE-200)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Exposure of Sensitive Information to an Unauthorized Actor vulnerabilities

Spotted an error? Tell us.