CVSS 7.8 CVE-2019-16905

CVSS 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

OpenSSH 7.7 through 7.9 and 8.x before 8.1, when compiled with an experimental key type, has a pre-authentication integer overflow if a client or server is configured to use a crafted XMSS key. This leads to memory corruption and local code execution because of an error in the XMSS key parsing algorithm. NOTE: the XMSS implementation is considered experimental in all released OpenSSH versions, and there is no supported way to enable it when building portable OpenSSH.

Affected Software:

• OpenSSH 7.7 - 7.9 & 8.0 - 8.1

References

• https://nvd.nist.gov/vuln/detail/CVE-2019-16905

• https://bugzilla.suse.com/show_bug.cgi?id=1153537

• https://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/sshkey-xmss.c

• https://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/sshkey-xmss.c.diff?r1=1.5&r2=1.6&f=h

• https://security.gentoo.org/glsa/201911-01

• https://security.netapp.com/advisory/ntap-20191024-0003/

• https://ssd-disclosure.com/archives/4033/ssd-advisory-openssh-pre-auth-xmss-integer-overflow

• https://www.openssh.com/releasenotes.html

• https://www.openwall.com/lists/oss-security/2019/10/09/1