#VU33132 Key management errors in Botan - CVE-2018-20187
Published: March 8, 2019 / Updated: August 3, 2020
Vulnerability identifier: #VU33132
Vulnerability risk: Medium
CVSSv4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2018-20187
CWE-ID: CWE-320
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerable software:
Botan
Botan
Software vendor:
Randombit
Randombit
Description
The vulnerability allows a remote non-authenticated attacker to gain access to sensitive information.
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.
Remediation
Install update from vendor's website.