CVE-2021-43398

Name	CVE-2021-43398
Description	DISPUTED Crypto++ (aka Cryptopp) 8.6.0 and earlier contains a timing leakage in MakePublicKey(). There is a clear correlation between execution time and private key length, which may cause disclosure of the length information of the private key. This might allow attackers to conduct timing attacks. NOTE: this report is disputed by the vendor and multiple third parties. The execution-time differences are intentional. A user may make a choice of a longer key as a tradeoff between strength and performance. In making this choice, the amount of information leaked to an adversary is of infinitesimal value.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, bugtraq, EDB, Metasploit, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, Mageia, GitHub code/issues, web search, more)
Debian Bugs	1000227

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
libcrypto++ (PTS)	stretch	5.6.4-7	vulnerable
	buster	5.6.4-8	vulnerable
	bullseye	8.4.0-1	vulnerable
	bookworm, sid	8.6.0-3	vulnerable

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
libcrypto++	source	(unstable)	(unfixed)	unimportant		1000227

Notes

https://github.com/weidai11/cryptopp/issues/1080
As per upstream believed to be the expected behaviour:
https://github.com/weidai11/cryptopp/issues/1080#issuecomment-996492222