Vulnerability in N/a

CVE-2025-27587

OpenSSL 3.0.0 through 3.3.2 on the PowerPC architecture is vulnerable to a Minerva attack, exploitable by measuring the time of signing of random messages using the EVP_DigestSign API, and then using the private key to extract the K value (nonce) from the signatures. Next, based on the bit size of the extracted nonce, one can compare the signing time of full-sized nonces to signatures that used smaller nonces, via statistical tests. There is a side-channel in the P-364 curve that allows private key extraction (also, there is a dependency between the bit size of K and the size of the side channel). NOTE: This CVE is disputed because the OpenSSL security policy explicitly notes that any side channels which require same physical system to be detected are outside of the threat model for the software. The timing signal is so small that it is infeasible to be detected without having the attacking process running on the same physical system.

EPSS: 0.004 (31.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N.

Affected products

  • N/a — versions n/a

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-27587?
CVE-2025-27587 is a medium-severity vulnerability in N/a, classified under CWE-385. CVSS score: 5.3/10. Published 2025-06-16.
How severe is CVE-2025-27587?
Medium severity. CVSS v3 base score is 5.3 out of 10.
Is CVE-2025-27587 known to be exploited?
3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.