CVE-2013-4207

Name	CVE-2013-4207
Description	Buffer overflow in sshbn.c in PuTTY before 0.63 allows remote SSH servers to cause a denial of service (crash) via an invalid DSA signature that is not properly handled during computation of a modular inverse and triggers the overflow during a division by zero by the bignum functionality, a different vulnerability than CVE-2013-4206.
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)
References	DSA-2736-1
NVD severity	medium (attack range: remote)
Debian Bugs	719070

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
filezilla (PTS)	jessie	3.9.0.5-1	fixed
	stretch	3.24.0-1	fixed
	buster, sid	3.33.0-1	fixed
putty (PTS)	jessie (security), jessie	0.63-10+deb8u1	fixed
	stretch	0.67-3	fixed
	buster, sid	0.70-4	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
filezilla	source	(unstable)	3.7.3-1	low		719070
putty	source	(unstable)	0.63-1	medium
putty	source	squeeze	0.60+2010-02-20-1+squeeze2	medium	DSA-2736-1
putty	source	wheezy	0.62-9+deb7u1	medium	DSA-2736-1

Notes

[squeeze] - filezilla <no-dsa> (Minor issue)
[wheezy] - filezilla <no-dsa> (Minor issue)
http://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/vuln-bignum-division-by-zero.html