Key management errors in Botan - CVE-2018-20187

Vulnerability details

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.

Affected software

How to mitigate CVE-2018-20187

External References

• https://botan.randombit.net/news.html
• https://botan.randombit.net/security.html
• https://github.com/crocs-muni/ECTester

Related Security Bulletins

• Key management errors in Randombit Botan
• Key management errors in botan (Alpine package)
• Fedora 29 update for botan2