`CVE-2018-15473` OpenSSH

Affected software	OpenSSH
Severity	5.9 Medium CVSS 3.1 3 scores
Weakness	CWE-362
Published	17 Aug 2018
Updated	17 Jun 2026

Description

OpenSSH through 7.7 is prone to a user enumeration vulnerability due to not delaying bailout for an invalid authenticating user until after the packet containing the request has been fully parsed, related to auth2-gss.c, auth2-hostbased.c, and auth2-pubkey.c.

Exploitation status

Working exploit published

A reviewed exploit catalogue lists ready-to-run exploit code for this CVE.

CISA KEV not listed
VulnCheck KEV not listed
CISA Vulnrichment exploitation: poc CISA recorded that an exploit has been demonstrated. Automatable: no, technical impact: partial.
Indexed PoC 36 indexed Published artifacts you can open, in Exploit-DB, GitHub PoC; first seen 2018-08-16.
EPSS 99% chance in 30 days A model's forecast, not a report of exploitation. Higher than 99.9% of all scored CVEs.

2 of these are GitHub repositories with fewer than 5 stars. They are listed for reference and don't count toward the exploitation status above.

Index	Artifact	Stars	First seen
GitHub PoC	Exploit written in Python for CVE-2018-15473 with threading and export formats	535	2018-08-21
Exploit-DB	OpenSSH < 7.7 - User Enumeration (2)		2018-12-04
GitHub PoC	OpenSSH 2.3 up to 7.4 Mass Username Enumeration (CVE-2018-15473).	160	2018-08-17
Exploit-DB	OpenSSH 2.3 < 7.7 - Username Enumeration		2018-08-21
GitHub PoC	Multi-threaded, IPv6 aware, wordlists/single-user username enumeration via CVE-2018-15473	117	2018-10-03
Exploit-DB	OpenSSH 2.3 < 7.7 - Username Enumeration (PoC)		2018-08-16
GitHub PoC	OpenSSH 2.3 < 7.7 - Username Enumeration	42	2020-11-29
GitHub PoC	OpenSSH 7.7 - Username Enumeration	17	2018-10-24
GitHub PoC	SSH User Enumerator in Python3, CVE-2018-15473, I updated the code of this exploit (https://www.exploit-db.com/exploits/45939) to work with python3 instead of python2.	4	2023-03-09
GitHub PoC	CVE-2018-15473 Exploit	3	2021-09-14

Waratek protection

Outside Waratek scope

A Java vulnerability, but not one Waratek protects. It affects only Java on a user's desktop (applets, Web Start, JavaFX, the installer), sits in a product the Waratek agent can't be installed into, or is in a package we don't expect in business applications. The decision below says which.

Protection none
Action not pursued none
Review human Researcher
Record active

Decided by	Manual classification of this CVE in the legacy dataset
Finding	A manual classification set this CVE's status to Outside Waratek scope, but the CVE names a tracked product.

Decided by

Manual classification of this CVE in the legacy dataset

Finding

A manual classification set this CVE's status to Outside Waratek scope, but the CVE names a tracked product.

CVSS

5.9 MEDIUM v3.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N 3 metrics

We show the highest score from the newest CVSS version. Scores from different versions can't be compared, and the first score listed is sometimes a 0.0 placeholder.

Version Score Band Vector Assigner Type

CVSS 3.1 5.9 MEDIUM CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N CISA-ADP Secondary published

CVSS 3.1 5.3 MEDIUM CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N NVD Primary

CVSS 2.0 5.0 none AV:N/AC:L/Au:N/C:P/I:N/A:N NVD Primary

Version	Score	Band	Vector	Assigner	Type
CVSS 3.1	5.9	MEDIUM	`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N`	CISA-ADP	Secondary	published
CVSS 3.1	5.3	MEDIUM	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N`	NVD	Primary
CVSS 2.0	5.0	none	`AV:N/AC:L/Au:N/C:P/I:N/A:N`	NVD	Primary

Affected software and releases

Products and versions

22 products, 28 version entries

Source	Vendor	Product	Scheme	Affected versions
nvd	canonical	ubuntu linux	generic	14.04 · 16.04 · 18.04
nvd	debian	debian linux	generic	8.0 · 9.0
nvd	netapp	aff baseboard management controller	generic	any version
nvd	netapp	cloud backup	generic	any version
nvd	netapp	clustered data ontap	generic	any version
nvd	netapp	cn1610 firmware	generic	any version
nvd	netapp	data ontap	generic	any version
nvd	netapp	data ontap edge	generic	any version
nvd	netapp	fas baseboard management controller	generic	any version
nvd	netapp	oncommand unified manager	generic	≥ 9.4
nvd	netapp	ontap select deploy	generic	any version
nvd	netapp	service processor	generic	any version
nvd	netapp	steelstore cloud integrated storage	generic	any version
nvd	netapp	storage replication adapter	generic	≥ 7.2
nvd	netapp	vasa provider	generic	≥ 7.2
nvd	netapp	virtual storage console	generic	≥ 7.2
nvd	openbsd	openssh	generic	≤ 7.7
nvd	oracle	sun zfs storage appliance kit	generic	8.8.6
nvd	redhat	enterprise linux desktop	generic	6.0 · 7.0
nvd	redhat	enterprise linux server	generic	6.0 · 7.0
nvd	redhat	enterprise linux workstation	generic	6.0 · 7.0
nvd	siemens	scalance x204rna firmware	generic	＜ 3.2.7

Source

Vendor

Product

Scheme

Affected versions

nvd

canonical

ubuntu linux

generic

14.04 · 16.04 · 18.04

nvd

debian

debian linux

generic

8.0 · 9.0

nvd

netapp

aff baseboard management controller

generic

any version

nvd

netapp

cloud backup

generic

any version

nvd

netapp

clustered data ontap

generic

any version

nvd

netapp

cn1610 firmware

generic

any version

nvd

netapp

data ontap

generic

any version

nvd

netapp

data ontap edge

generic

any version

nvd

netapp

fas baseboard management controller

generic

any version

nvd

netapp

oncommand unified manager

generic

≥ 9.4

nvd

netapp

ontap select deploy

generic

any version

nvd

netapp

service processor

generic

any version

nvd

netapp

steelstore cloud integrated storage

generic

any version

nvd

netapp

storage replication adapter

generic

≥ 7.2

nvd

netapp

vasa provider

generic

≥ 7.2

nvd

netapp

virtual storage console

generic

≥ 7.2

nvd

openbsd

openssh

generic

≤ 7.7

nvd

oracle

sun zfs storage appliance kit

generic

8.8.6

nvd

redhat

enterprise linux desktop

generic

6.0 · 7.0

nvd

redhat

enterprise linux server

generic

6.0 · 7.0

nvd

redhat

enterprise linux workstation

generic

6.0 · 7.0

nvd

siemens

scalance x204rna firmware

generic

＜ 3.2.7

Earlier manual review

A reviewer classified this CVE in an older dataset. We kept the labels and products below, but not the reviewer's reasoning.

## Manual Classification Context **Products:** OPENSSH

References

URL	Tags
http://www.openwall.com/lists/oss-security/2018/08/15/5	Mailing List, Patch, Third Party Advisory
http://www.securityfocus.com/bid/105140	Broken Link, Third Party Advisory, VDB Entry
http://www.securitytracker.com/id/1041487	Broken Link, Patch, Third Party Advisory, VDB Entry
https://access.redhat.com/errata/RHSA-2019:0711	Third Party Advisory
https://access.redhat.com/errata/RHSA-2019:2143	Third Party Advisory
https://bugs.debian.org/906236	Issue Tracking, Mailing List, Patch, Third Party Advisory
https://cert-portal.siemens.com/productcert/pdf/ssa-412672.pdf	Patch, Third Party Advisory
https://github.com/openbsd/src/commit/779974d35b4859c07bc3cb8a12c74b43b0a7d1e0	Patch
https://lists.debian.org/debian-lts-announce/2018/08/msg00022.html	Mailing List, Third Party Advisory
https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2018-0011	Third Party Advisory

URL

Timeline

Published	2018-08-17	By the CVE Program.
NVD record modified	2026-06-17	NVD's own last-modified date for this record.

Published

2018-08-17

By the CVE Program.

NVD record modified

2026-06-17

NVD's own last-modified date for this record.

How VRT decided (5 of 24 rules ran)

5 of 24 rules ran. The rest didn't run because an earlier rule had already settled the CVE.

# Rule Outcome Status Detail

identity: Does this identifier describe a vulnerability at all? the first rule that matches decides

1 rejected no match CVE Program withdrawal of this identifier

scope: Is it a vulnerability Waratek protects? the first rule that matches decides

2 armr-patch-file no match An ARMR patch file on disk for this CVE

3 armr-secure-rule-file no match An ARMR security-rule template on disk for this CVE

4 manual-classification no match A researcher's recorded decision for this specific CVE

5 manual classification decided it matched Outside Waratek scope Found in legacy manual classifications

6 non-java-upstream not reached A root cause in non-Java code: an OS kernel, a C library, or a bundled runtime

7 oracle-component not reached The defect being in a component of a tracked product the agent does not reach: JavaFX, the Java SE installer, the JInitiator browser plug-in, the native WebLogic proxy plug-in, or a native part of Oracle Application Server or Collaboration Suite (HTTP Server, Web Cache, Internet Directory, mail and calendar servers). Oracle gives these no CPE of their own and names them only in the description.

8 java-client-side not reached Oracle's own risk-matrix note saying the CVE is reached only through untrusted code in the Java sandbox (applets, Web Start) or only through a client installation of Java, so a server running its own trusted code is not exposed

9 osv-maven not reached An OSV.dev record of this CVE affecting a package published to Maven Central. When every such package is one business applications do not use (Minecraft mods and launchers, Fastjson) and no tracked product is named by CPE, it settles the CVE as Outside Waratek scope instead

10 cna-maven-package not reached An affected Maven artifact named by the CNA itself

11 known-cpe-product not reached An NVD CPE naming a product ARMR tracks

12 cna-cpe-product not reached A CPE the CNA published naming a tracked product. Oracle publishes these on advisory day, months before NVD.

13 oracle-advisory-family not reached A tracked product family named in Oracle's own risk matrix. CPE cannot carry a suite name, only a module.

14 cna-named-product not reached A tracked product named in words by the CVE's own CNA, on a record with no CPE yet. Apache and Eclipse publish these on advisory day, before NVD adds CPE data.

15 non-deployable-product not reached The only affected product being a sealed appliance image, where Java runs but no -javaagent can be attached

16 unmatched-product not reached No tracked product matched above, and none present at all

disposition: What do we do about one that is? every rule runs

17 patch-hint not reached A reference pointing at the upstream fix: a commit, a PR, a Red Hat bug

18 open-source-maven not reached The affected package being open source on Maven, so the fix can be read

19 poc-derivable not reached An indexed exploit clearing the evidence bar to reverse-engineer, where there is no source to read

20 no-exploit not reached Nothing to build a rule from yet: no published exploit, no CISA record of exploitation and no source-level change to read

21 secure-rule-match not reached A vulnerability class already blocked by an ARMR security rule

22 exploited-no-fix-or-poc not reached Somebody exploiting this CVE (a CISA or VulnCheck KEV listing, or a CISA verdict of active exploitation), with no fix, source code or PoC to build a rule from

23 below-action-threshold not reached Medium or Low severity, no CISA or VulnCheck KEV listing, no PoC clearing the evidence bar, no CISA verdict, no Oracle advisory

24 no-exploit-published not reached Exploit code for this candidate, published in a reviewed catalogue or a GitHub repository with 5 or more stars, or in use per CISA or VulnCheck; not only a CISA verdict, a forecast, or nothing at all

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