SB2019010602 - Key management errors in botan (Alpine package)

Description

This security bulletin contains information about 1 security vulnerability.

1) Key management errors (CVE-ID: CVE-2018-20187)

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.

References

• https://git.alpinelinux.org/aports/commit/?id=1c18797cef1fa8638c3386991406611d0e17ea19
• https://git.alpinelinux.org/aports/commit/?id=533e0d57cb72dfca358b0e030e8332f67250b2f9