CVE-2025-1860 identifies a cryptographic vulnerability in the ZEFRAM Data::Entropy Perl module, specifically versions 0.007 and earlier. The vulnerability arises from the use of the standard Perl rand() function as the default entropy source for cryptographic operations. The rand() function is a pseudo-random number generator (PRNG) that is not designed to be cryptographically secure, meaning its output can be predicted or reproduced by attackers with sufficient knowledge or access. This weakness falls under CWE-338, which concerns the use of cryptographically weak PRNGs. The consequence is that cryptographic functions relying on Data::Entropy for randomness may generate predictable keys, nonces, or other cryptographic values, severely undermining confidentiality and integrity. The CVSS v3.1 base score of 7.7 (high severity) reflects the vulnerability's potential to compromise confidentiality and integrity without requiring user interaction or privileges, though it requires local access (AV:L). No known exploits are currently reported in the wild, and no patches have been published yet. The vulnerability was reserved in early March 2025 and published later that month. This issue is critical for any applications or systems using the affected Data::Entropy versions for cryptographic purposes, as it can lead to predictable cryptographic outputs, enabling attackers to decrypt sensitive data, forge signatures, or bypass authentication mechanisms.

For European organizations, the impact of this vulnerability depends on the extent to which they use the ZEFRAM Data::Entropy Perl module in their software stacks, particularly for cryptographic operations. Organizations relying on Perl-based applications for security-critical functions such as encryption, digital signatures, or secure random number generation may face significant risks. The use of a weak PRNG can lead to exposure of sensitive data, unauthorized data modification, and potential compromise of authentication systems. This is especially critical for sectors handling sensitive personal data under GDPR, such as finance, healthcare, and government services. The vulnerability's requirement for local access limits remote exploitation but raises concerns for insider threats or compromised internal systems. Additionally, the lack of patches means organizations must proactively identify and mitigate usage. The high confidentiality and integrity impact could lead to data breaches, regulatory penalties, and reputational damage. Given the widespread use of Perl in legacy and specialized applications across Europe, the threat is non-trivial and warrants immediate attention.

1. Immediate code audit: Organizations should audit their codebases and dependencies to identify any usage of the ZEFRAM Data::Entropy module version 0.007 or earlier. 2. Replace or update entropy sources: Where Data::Entropy is used for cryptographic purposes, replace the default rand() entropy source with a cryptographically secure PRNG, such as those provided by the Crypt::PRNG or Crypt::Random Perl modules, or system-level secure random sources like /dev/urandom or Windows CryptGenRandom. 3. Isolate vulnerable components: If immediate replacement is not feasible, isolate affected components to minimize local access and privilege escalation risks. 4. Monitor and restrict local access: Strengthen internal access controls and monitoring to detect and prevent unauthorized local access that could exploit this vulnerability. 5. Engage with vendors or maintainers: Track updates from ZEFRAM or CPAN maintainers for patches or new releases addressing this issue. 6. Implement defense-in-depth: Use layered security controls such as encryption at higher layers, multi-factor authentication, and network segmentation to reduce the impact of potential cryptographic weaknesses. 7. Educate developers: Raise awareness among developers about the importance of using cryptographically secure PRNGs and proper entropy sources in cryptographic implementations.