CVE-2018-20187: Botan Project Botan

Medium severity, CVSS 5.9. EPSS: 1.5% chance of exploitation in the next 30 days.

A side-channel issue was discovered in Botan before 2.9.0. An attacker capable of precisely measuring the time taken for ECC key generation may be able to derive information about the high bits of the secret key, as the function to derive the public point from the secret scalar uses an unblinded Montgomery ladder whose loop iteration count depends on the bitlength of the secret. This issue affects only key generation, not ECDSA signatures or ECDH key agreement.

Affected products

• Botan Project Botan: before 2.9.0 (fixed in 2.9.0)

Published 2019-03-08. Last modified 2026-06-17.