CVE-2018-20187

Name	CVE-2018-20187
Description	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.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
Debian Bugs	918732

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
botan (PTS)	buster	2.9.0-2	fixed
	bullseye	2.17.3+dfsg-2	fixed
	bookworm	2.19.3+dfsg-1	fixed
	sid, trixie	2.19.4+dfsg-1	fixed
botan1.10 (PTS)	jessie, jessie (lts)	1.10.8-2+deb8u2	fixed
	stretch (security), stretch (lts), stretch	1.10.17-1+deb9u1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Debian Bugs
botan	source	experimental	2.9.0-1
botan	source	(unstable)	2.9.0-2	918732
botan1.10	source	(unstable)	(not affected)

Notes

- botan1.10 <not-affected> (Vulnerable code introduced in 1.11.20)
https://github.com/randombit/botan/pull/1792
https://github.com/randombit/botan/commit/70aa7303acfff9eefc24598c289a84db3579ebd1