Information disclosure in Wolfssl

CVE-2025-7394

In the OpenSSL compatibility layer implementation, the function RAND_poll() was not behaving as expected and leading to the potential for predictable values returned from RAND_bytes() after fork() is called. This can lead to weak or predictable random numbers generated in applications that are both using RAND_bytes() and doing fork() operations. This only affects applications explicitly calling RAND_bytes() after fork() and does not affect any internal TLS operations. Although RAND_bytes() documentation in OpenSSL calls out not being safe for use with fork() without first calling RAND_poll(), an additional code change was also made in wolfSSL to make RAND_bytes() behave similar to OpenSSL after a fork() call without calling RAND_poll(). Now the Hash-DRBG used gets reseeded after detecting running in a new process. If making use of RAND_bytes() and calling fork() we recommend updating to the latest version of wolfSSL. Thanks to Per Allansson from Appgate for the report.

Vulnerability class: Information Disclosure

EPSS: 0.004 (31.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-7394?
CVE-2025-7394 is a critical-severity vulnerability in Wolfssl, classified under Information Disclosure. CVSS score: 9.8/10. Published 2025-07-18.
How severe is CVE-2025-7394?
Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2025-7394 known to be exploited?
7 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.