CVE-2019-16905
HIGH severity · CVSS 7.8 · Integer overflow
7.8CVSS HIGH
Summary
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.
Impact & exploitability
Attack vectorLocal
Attack complexityLow
Privileges requiredLow
User interactionNone
Confidentiality impactHigh
Integrity impactHigh
Availability impactHigh
Exploit probability (EPSS)2%
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Affected products we track (1)
Recommendation
Apply the vendor fix promptly. Open any affected product above for its exact safe version.
Official patch: https://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/sshkey-xmss.c.diff?r1=1.5&r2=1.6&f=h ↗
Additional information
- NVD record
- https://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/sshkey-xmss.c.diff?r1=1.5&r2=1.6&f=hPatch
- https://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/sshkey-xmss.cAdvisory
- https://bugzilla.suse.com/show_bug.cgi?id=1153537Advisory
- https://cert-portal.siemens.com/productcert/pdf/ssa-412672.pdfAdvisory
- https://security.gentoo.org/glsa/201911-01Advisory
- https://security.netapp.com/advisory/ntap-20191024-0003/Advisory
- https://www.openssh.com/releasenotes.html
- https://ssd-disclosure.com/archives/4033/ssd-advisory-openssh-pre-auth-xmss-integer-overflowAdvisory