Resource exhaustion in OpenBSD OpenSSH
CVE-2016-8858
The kex_input_kexinit function in kex.c in OpenSSH 6.x and 7.x through 7.3 allows remote attackers to cause a denial of service (memory consumption) by sending many duplicate KEXINIT requests. NOTE: a third party reports that "OpenSSH upstream does not consider this as a security issue."
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.295 (98.1th percentile), scored .
Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 98th percentile — 98.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.295 · newest: 0.295 · change: 0.000
Affected products
- OpenBSD OpenSSH — versions 6.8, 6.9, 7.0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- www.securityfocus.com/bid/93776 (VDB Entry, Third Party Advisory, vdb-entry)
- www.openwall.com/lists/oss-security/2016/10/20/1 (mailing-list, Mailing List, Third Party Advisory)
- security.netapp.com/advisory/ntap-20180201-0001/ (Third Party Advisory)
- www.openwall.com/lists/oss-security/2016/10/19/3 (mailing-list, Mailing List, Third Party Advisory)
- cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/kex.c.diff (Issue Tracking, Vendor Advisory)
- github.com/openssh/openssh-portable/commit/ec165c392ca54317dbe3064a8c200de6531e… (Patch, Third Party Advisory, Issue Tracking)
- ftp.openbsd.org/pub/OpenBSD/patches/6.0/common/013_ssh_kexinit.patch.sig (Patch, Vendor Advisory)
- security.FreeBSD.org/advisories/FreeBSD-SA-16:33.openssh.asc (vendor-advisory, Third Party Advisory)
- www.securitytracker.com/id/1037057 (VDB Entry, Third Party Advisory, vdb-entry)
- security.gentoo.org/glsa/201612-18 (vendor-advisory, Third Party Advisory)
Frequently asked questions
- What is CVE-2016-8858?
- CVE-2016-8858 is a high-severity vulnerability in OpenBSD OpenSSH, classified under CWE-399. CVSS score: 7.5/10. Published 2016-12-09.
- How severe is CVE-2016-8858?
- High severity. CVSS v3 base score is 7.5 out of 10.
- Is CVE-2016-8858 known to be exploited?
- 7 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.