CVE-2016-8858
high
CVSS v3
7.5
CVSS v4 NEW
—
VIR risk
7.5
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."
Predictions
Exploit likelihood
83%
Patch ETA
—
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| sles | affected | | |
| debian | bookworm | fixed | 1:7.3p1-2 |
| debian | bullseye | fixed | 1:7.3p1-2 |
| debian | forky | fixed | 1:7.3p1-2 |
| debian | sid | fixed | 1:7.3p1-2 |
| debian | trixie | fixed | 1:7.3p1-2 |
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
- http://www.openwall.com/lists/oss-security/2016/10/19/3
- http://www.openwall.com/lists/oss-security/2016/10/20/1
- http://www.securityfocus.com/bid/93776
- http://www.securitytracker.com/id/1037057
- https://bugzilla.redhat.com/show_bug.cgi?id=1384860
- https://cert-portal.siemens.com/productcert/pdf/ssa-412672.pdf
- 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
- https://security.gentoo.org/glsa/201612-18
- https://security.netapp.com/advisory/ntap-20180201-0001/
- https://www.suse.com/security/cve/CVE-2016-8858.html
- https://security-tracker.debian.org/tracker/CVE-2016-8858
CWEs
CWE-399 CWE-400
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.