CVE-2019-16905
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (2.23%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 2.23% probability · 83th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-190
- Affected
- openbsd/openssh · netapp/cloud backup · netapp/steelstore cloud integrated storage · siemens/scalance x204rna firmware · siemens/scalance x204rna ecc firmware
- Source
- cve@mitre.org
EPSS 2.2% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://bugzilla.suse.com/show_bug.cgi?id=1153537Issue Tracking, Third Party Advisory
- https://cert-portal.siemens.com/productcert/pdf/ssa-412672.pdfThird Party Advisory
- https://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/sshkey-xmss.cRelease Notes, Vendor Advisory
- https://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/sshkey-xmss.c.diff?r1=1.5&r2=1.6&f=hPatch
- https://security.gentoo.org/glsa/201911-01Third Party Advisory
- https://security.netapp.com/advisory/ntap-20191024-0003/Third Party Advisory
- https://ssd-disclosure.com/archives/4033/ssd-advisory-openssh-pre-auth-xmss-integer-overflowExploit, Third Party Advisory
- https://www.openssh.com/releasenotes.htmlRelease Notes
- https://www.openwall.com/lists/oss-security/2019/10/09/1Mailing List, Third Party Advisory
- https://bugzilla.suse.com/show_bug.cgi?id=1153537Issue Tracking, Third Party Advisory
- https://cert-portal.siemens.com/productcert/pdf/ssa-412672.pdfThird Party Advisory
- https://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/sshkey-xmss.cRelease Notes, Vendor Advisory
- https://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/sshkey-xmss.c.diff?r1=1.5&r2=1.6&f=hPatch
- https://security.gentoo.org/glsa/201911-01Third Party Advisory
- https://security.netapp.com/advisory/ntap-20191024-0003/Third Party Advisory
- https://ssd-disclosure.com/archives/4033/ssd-advisory-openssh-pre-auth-xmss-integer-overflowExploit, Third Party Advisory
- https://www.openssh.com/releasenotes.htmlRelease Notes
- https://www.openwall.com/lists/oss-security/2019/10/09/1Mailing List, Third Party Advisory
- https://cert-portal.siemens.com/productcert/html/ssa-398330.html
- https://cert-portal.siemens.com/productcert/html/ssa-412672.html
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.