CVE-2016-8858
HIGH
7.5
CVSS Score
Published: December 9, 2016 at 12:00 AM UTC
Updated: June 17, 2026 at 12:55 AM UTC
1 product affected across 1 vendorOpenSSH
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Severity
HIGH7.5
Exploit prediction
EPSS 29%
SSVC
No known exploit
Description
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."
Remediation
No guide yetNo remediation guidance has been written for this CVE yet. What the record does show:
Patch and advisory references
- http://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/kex.c.diff?r1=1.126&r2=1.127&f=h
- http://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/kex.c?rev=1.127&content-type=text/x-cvsweb-markup
- https://ftp.openbsd.org/pub/OpenBSD/patches/6.0/common/013_ssh_kexinit.patch.sig
- https://github.com/openssh/openssh-portable/commit/ec165c392ca54317dbe3064a8c200de6531e89ad
- https://security.FreeBSD.org/advisories/FreeBSD-SA-16:33.openssh.asc
References (13)
Issue TrackingVendor Advisory
Source: [email protected]
http://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/kex.c.diff?r1=1.126&r2=1.127&f=hIssue TrackingVendor Advisory
Source: [email protected]
http://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/kex.c?rev=1.127&content-type=text/x-cvsweb-markupMailing ListThird Party Advisory
Source: [email protected]
http://www.openwall.com/lists/oss-security/2016/10/19/3Mailing ListThird Party Advisory
Source: [email protected]
http://www.openwall.com/lists/oss-security/2016/10/20/1SSVC — Action Prioritization
SSVCNo known exploitAutomatablePartial impact
SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.
CVSS
7.5HIGHCISA-ADP
- Attack Vector
- NETWORK
- Complexity
- LOW
- Privileges
- NONE
- User Interaction
- NONE
- Scope
- UNCHANGED
- Confidentiality
- NONE
- Integrity
- NONE
- Availability
- HIGH
Vector?
Quick Info
StatusMODIFIED
CWE
CWE-399CWE-400
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