CVE-2016-6210

CRITICALNVD 5.99.0
EchelonGraph scoreHIGH confidence

“▲” beside the score: it is higher than NVD's CVSS score.

Score elevated to 9.0 because EPSS predicted 89% probability of exploitation within the next 30 days (99th percentile of EPSS-scored CVEs) when EchelonGraph scored this CVE. NVD baseline CVSS 5.9 retained for reference. Confidence: see factors.

Triggered by: EPSS exploit prediction (continuous uplift above 30%)
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3
Weaponized

Also known asEUVD-2016-7143 (ENISA EUVD) · GHSA-f525-65h3-3qjh (GitHub Security Advisories)Source: ENISA EUVD

9.0EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • 456 internet-facing services (distinct ip:port) on record running an affected version — derived from Shodan data (© Shodan); a patched service can stay counted while its port stays open
  • High exploitation likelihood — EPSS 89%
  • Public exploit code is available (Metasploit, other public proof-of-concept code)
CISA-KEV: Not listedEPSS PROB: 89%CVSS: 5.9Exploit: Metasploit · other public PoCExposed services: 456

A fix is available — apply it.

sshd in OpenSSH before 7.3, when SHA256 or SHA512 are used for user password hashing, uses BLOWFISH hashing on a static password when the username does not exist, which allows remote attackers to enumerate users by leveraging the timing difference between responses when a large password is provided.

Internet exposure · derived from Shodan data

456 internet-facing services (distinct ip:port) on record running a version that maps to CVE-2016-6210, in our KEV-Exposure radar’s Shodan-derived sample.

across 31 hosting countries (China, United States, Germany, Japan, France)top: openssh
See the KEV-Exposure radar →Derived from Shodan data. Shodan data is owned by Shodan, which holds its copyright (© Shodan). EchelonGraph claims no ownership of it or copyright in it. Aggregate, host-redacted.

How it counts: every 12 hours, when Shodan query credits allow, the radar runs one Shodan query per tracked product, reads up to 100 ip:port services per query, and keeps a service when its banner version matches a CISA-KEV or high-EPSS CVE; a service is dropped when neither a search nor a Shodan InternetDB port re-check has refreshed it for 21 days. A re-check that finds the port still listed by Shodan InternetDB refreshes the service without re-reading the banner, so a patched service can stay counted while its port stays open. A count is a banner-version inference over a sample, not an exploit test and not an internet-wide census, and the unit is a service, not a machine: a machine answering on two ports counts twice.

CVSS v3
5.9
EG Score
9.0CRITICALhigh confidence
EG Risk
62
EG Risk 62/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity59% × 45%
Impact severity (EG Severity): CVSS 5.9 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation89% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
89%
EPSS %ILE
99th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (9.0): severity, escalated by confirmed exploitation. This CVE's 9.0 is EPSS's lift toward 9.0 from its impact severity (EG Severity, CVSS 5.9 MEDIUM): a likelihood of exploitation, not impact.

EG Severity
5.9 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
89% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-11). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines.

Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

February 13, 2017

Last Modified

June 17, 2026

Advisory Details (9)

Auto-updated Oct 14, 2026
Patch available. Sources: redhat.
Web page

OpenSSHd 7.2p2 - Username Enumeration - Linux remote Exploit

https://www.exploit-db.com/exploits/40113/
Web page

OpenSSH: Multiple vulnerabilities (GLSA 201612-18) — Gentoo security

https://security.gentoo.org/glsa/201612-18
Red HatMentions a patch (unverified)

Affected: Red Hat Enterprise Linux 6.

https://access.redhat.com/errata/RHSA-2017:2563
Red HatMentions a patch (unverified)

Affected: Red Hat Enterprise Linux 7.

https://access.redhat.com/errata/RHSA-2017:2029
Web page

CVE-2016-6210 - PSIRT.COM

http://www.securityfocus.com/bid/91812
Web page

[SECURITY] [DSA 3626-1] openssh security update

http://www.debian.org/security/2016/dsa-3626
Web page

Full Disclosure: opensshd - user enumeration

http://seclists.org/fulldisclosure/2016/Jul/51

Vendor Advisories for CVE-2016-6210(2)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(3)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntuopenssh-server (1:5.9p1-5ubuntu1.10) @ precise2026-11-11ubuntu
redhatopenssh-0:5.3p1-123.el6_92017-08-31redhat
redhatopenssh-0:7.4p1-11.el72017-08-01redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(9 across 9 ecosystems)
Alpine:v3.2(1)
PackageVulnerable rangeFix by version rangeDependents
openssh—
  • every version up to 6.8_p1-r7: fixed in 6.8_p1-r7
—
Alpine:v3.3(1)
PackageVulnerable rangeFix by version rangeDependents
openssh—
  • every version up to 7.2_p2-r1: fixed in 7.2_p2-r1
—
Alpine:v3.4(1)
PackageVulnerable rangeFix by version rangeDependents
openssh—
  • every version up to 7.2_p2-r1: fixed in 7.2_p2-r1
—
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
openssh—
  • every version up to 1:7.2p2-6: fixed in 1:7.2p2-6
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
openssh—
  • every version up to 1:7.2p2-6: fixed in 1:7.2p2-6
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
openssh—
  • every version up to 1:7.2p2-6: fixed in 1:7.2p2-6
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
openssh—
  • every version up to 1:7.2p2-6: fixed in 1:7.2p2-6
—
Debian:7(1)
PackageVulnerable rangeFix by version rangeDependents
openssh1:6.0p1-4, 1:6.0p1-4+deb7u1, 1:6.0p1-4+deb7u2, 1:6.0p1-4+deb7u3, 1:6.0p1-4+deb7u4
  • every version up to 1:6.0p1-4+deb7u5: fixed in 1:6.0p1-4+deb7u5
—
Debian:8(1)
PackageVulnerable rangeFix by version rangeDependents
openssh1:6.7p1-5, 1:6.7p1-5+deb8u1, 1:6.7p1-5+deb8u2
  • every version up to 1:6.7p1-5+deb8u3: fixed in 1:6.7p1-5+deb8u3
—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(3)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 17× in last 7d / 70× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed its CVE.org record (CNA or CISA ADP). An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). "EchelonGraph re-scored" is our own recompute of this CVE's score, not an update from a source, and is not counted in the refreshes above. Most recent first.

Showing the most recent 100 of 176 rows on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 76 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-12 07:06 UTCEchelonGraph re-scored
  2. 2026-11-12 07:06 UTCVendor advisory
  3. 2026-11-12 07:06 UTCGHSA enrichmentGHSA-f525-65h3-3qjh · GitHub severity MODERATE · GitHub CVSS 5.9
  4. 2026-11-11 16:28 UTCEPSS rescoreEPSS 89% · 99th percentile
  5. 2026-11-11 07:08 UTCEchelonGraph re-scored
  6. 2026-11-11 07:08 UTCVendor advisory
  7. 2026-11-11 07:08 UTCGHSA enrichmentGHSA-f525-65h3-3qjh · GitHub severity MODERATE · GitHub CVSS 5.9
  8. 2026-11-10 07:09 UTCEchelonGraph re-scored
  9. 2026-11-10 07:09 UTCVendor advisory
  10. 2026-11-10 07:09 UTCGHSA enrichmentGHSA-f525-65h3-3qjh · GitHub severity MODERATE · GitHub CVSS 5.9
  11. 2026-11-09 07:11 UTCEchelonGraph re-scored
  12. 2026-11-09 07:11 UTCVendor advisory
  13. 2026-11-09 07:11 UTCGHSA enrichmentGHSA-f525-65h3-3qjh · GitHub severity MODERATE · GitHub CVSS 5.9
  14. 2026-11-08 16:29 UTCEPSS rescoreEPSS 89% · 99th percentile
  15. 2026-11-08 07:14 UTCEchelonGraph re-scored
  16. 2026-11-08 07:14 UTCVendor advisory
  17. 2026-11-08 07:14 UTCGHSA enrichmentGHSA-f525-65h3-3qjh · GitHub severity MODERATE · GitHub CVSS 5.9
  18. 2026-11-07 16:29 UTCEPSS rescoreEPSS 89% · 99th percentile
  19. 2026-11-07 07:14 UTCEchelonGraph re-scored
  20. 2026-11-07 07:14 UTCVendor advisory
  21. 2026-11-07 07:14 UTCGHSA enrichmentGHSA-f525-65h3-3qjh · GitHub severity MODERATE · GitHub CVSS 5.9
  22. 2026-11-06 07:17 UTCEchelonGraph re-scored
  23. 2026-11-06 07:17 UTCVendor advisory
  24. 2026-11-06 07:17 UTCGHSA enrichmentGHSA-f525-65h3-3qjh · GitHub severity MODERATE · GitHub CVSS 5.9
  25. 2026-11-05 16:27 UTCEPSS rescoreEPSS 89% · 99th percentile
Show 75 more
  1. 2026-11-05 07:21 UTCEchelonGraph re-scored
  2. 2026-11-05 07:21 UTCVendor advisory
  3. 2026-11-05 07:21 UTCGHSA enrichmentGHSA-f525-65h3-3qjh · GitHub severity MODERATE · GitHub CVSS 5.9
  4. 2026-11-04 16:27 UTCEPSS rescoreEPSS 89% · 99th percentile
  5. 2026-11-04 07:25 UTCEchelonGraph re-scored
  6. 2026-11-04 07:25 UTCVendor advisory
  7. 2026-11-04 07:25 UTCGHSA enrichmentGHSA-f525-65h3-3qjh · GitHub severity MODERATE · GitHub CVSS 5.9
  8. 2026-11-03 07:29 UTCEchelonGraph re-scored
  9. 2026-11-03 07:29 UTCVendor advisory
  10. 2026-11-03 07:29 UTCGHSA enrichmentGHSA-f525-65h3-3qjh · GitHub severity MODERATE · GitHub CVSS 5.9
  11. 2026-11-02 11:55 UTCOSV refresh
  12. 2026-11-02 07:33 UTCEchelonGraph re-scored
  13. 2026-11-02 07:33 UTCVendor advisory
  14. 2026-11-02 07:33 UTCGHSA enrichmentGHSA-f525-65h3-3qjh · GitHub severity MODERATE · GitHub CVSS 5.9
  15. 2026-11-01 07:38 UTCEchelonGraph re-scored
  16. 2026-11-01 07:38 UTCVendor advisory
  17. 2026-11-01 07:38 UTCGHSA enrichmentGHSA-f525-65h3-3qjh · GitHub severity MODERATE · GitHub CVSS 5.9
  18. 2026-10-31 16:27 UTCEPSS rescoreEPSS 89% · 99th percentile
  19. 2026-10-31 07:41 UTCEchelonGraph re-scored
  20. 2026-10-31 07:41 UTCVendor advisory
  21. 2026-10-31 07:41 UTCGHSA enrichmentGHSA-f525-65h3-3qjh · GitHub CVSS 5.9
  22. 2026-10-30 07:46 UTCEchelonGraph re-scored
  23. 2026-10-30 07:46 UTCVendor advisory
  24. 2026-10-30 07:46 UTCGHSA enrichmentGHSA-f525-65h3-3qjh · GitHub CVSS 5.9
  25. 2026-10-29 07:50 UTCEchelonGraph re-scored
  26. 2026-10-29 07:50 UTCVendor advisory
  27. 2026-10-29 07:50 UTCGHSA enrichmentGHSA-f525-65h3-3qjh · GitHub CVSS 5.9
  28. 2026-10-28 16:26 UTCEPSS rescoreEPSS 89% · 99th percentile
  29. 2026-10-28 07:55 UTCEchelonGraph re-scored
  30. 2026-10-28 07:55 UTCVendor advisory
  31. 2026-10-28 07:55 UTCGHSA enrichmentGHSA-f525-65h3-3qjh · GitHub CVSS 5.9
  32. 2026-10-27 08:00 UTCEchelonGraph re-scored
  33. 2026-10-27 08:00 UTCVendor advisory
  34. 2026-10-27 08:00 UTCGHSA enrichmentGHSA-f525-65h3-3qjh · GitHub CVSS 5.9
  35. 2026-10-26 05:41 UTCVendor advisory
  36. 2026-10-26 05:40 UTCGHSA enrichmentGHSA-f525-65h3-3qjh · GitHub CVSS 5.9
  37. 2026-10-25 19:45 UTCEchelonGraph re-scored
  38. 2026-10-25 16:27 UTCEPSS rescoreEPSS 89% · 99th percentile
  39. 2026-10-25 05:43 UTCEchelonGraph re-scored
  40. 2026-10-25 05:43 UTCVendor advisory
  41. 2026-10-25 05:42 UTCGHSA enrichmentGHSA-f525-65h3-3qjh · GitHub CVSS 5.9
  42. 2026-10-24 05:47 UTCEchelonGraph re-scored
  43. 2026-10-24 05:47 UTCVendor advisory
  44. 2026-10-24 05:46 UTCGHSA enrichmentGHSA-f525-65h3-3qjh · GitHub CVSS 5.9
  45. 2026-10-23 05:47 UTCEchelonGraph re-scored
  46. 2026-10-23 05:47 UTCVendor advisory
  47. 2026-10-23 05:47 UTCGHSA enrichmentGHSA-f525-65h3-3qjh · GitHub CVSS 5.9
  48. 2026-10-22 05:51 UTCEchelonGraph re-scored
  49. 2026-10-22 05:51 UTCVendor advisory
  50. 2026-10-22 05:51 UTCGHSA enrichmentGHSA-f525-65h3-3qjh · GitHub CVSS 5.9
  51. 2026-10-21 16:27 UTCEPSS rescoreEPSS 89% · 99th percentile
  52. 2026-10-21 05:56 UTCEchelonGraph re-scored
  53. 2026-10-21 05:56 UTCVendor advisory
  54. 2026-10-21 05:55 UTCGHSA enrichmentGHSA-f525-65h3-3qjh · GitHub CVSS 5.9
  55. 2026-10-20 05:59 UTCEchelonGraph re-scored
  56. 2026-10-20 05:59 UTCVendor advisory
  57. 2026-10-20 05:58 UTCGHSA enrichmentGHSA-f525-65h3-3qjh · GitHub CVSS 5.9
  58. 2026-10-19 06:02 UTCEchelonGraph re-scored
  59. 2026-10-19 06:02 UTCVendor advisory
  60. 2026-10-19 06:02 UTCGHSA enrichmentGHSA-f525-65h3-3qjh · GitHub CVSS 5.9
  61. 2026-10-18 06:05 UTCEchelonGraph re-scored
  62. 2026-10-18 06:05 UTCVendor advisory
  63. 2026-10-18 06:05 UTCGHSA enrichmentGHSA-f525-65h3-3qjh · GitHub CVSS 5.9
  64. 2026-10-17 06:06 UTCEchelonGraph re-scored
  65. 2026-10-17 06:06 UTCVendor advisory
  66. 2026-10-17 06:05 UTCGHSA enrichmentGHSA-f525-65h3-3qjh · GitHub CVSS 5.9
  67. 2026-10-16 06:09 UTCEchelonGraph re-scored
  68. 2026-10-16 06:09 UTCVendor advisory
  69. 2026-10-16 06:08 UTCGHSA enrichmentGHSA-f525-65h3-3qjh · GitHub CVSS 5.9
  70. 2026-10-15 16:26 UTCEPSS rescoreEPSS 89% · 99th percentile
  71. 2026-10-15 04:45 UTCEchelonGraph re-scored
  72. 2026-10-15 04:45 UTCVendor advisory
  73. 2026-10-15 04:45 UTCGHSA enrichmentGHSA-f525-65h3-3qjh · GitHub CVSS 5.9
  74. 2026-10-14 16:27 UTCEPSS rescoreEPSS 89% · 99th percentile
  75. 2026-10-14 00:38 UTCEchelonGraph re-scored

Publicly available exploits

(6 references)

Public exploit code is referenced for this CVE (1 Metasploit module, 2 Exploit-DB entries, 2 GitHub PoCs), as is 1 GitHub checker repository. A GitHub repository named or described as a checker or scanner checks whether a system is affected; it is not necessarily exploit code. Defenders should treat patch urgency accordingly.

  • Metasploitauxiliary/scanner/ssh/ssh_enumusers✓ verified
    Published Apr 23, 2014

    SSH Username Enumeration

    Open source ↗
  • GitHub PoCserexp/poc-CVE20166210
    Published May 2, 2026

    CVE-2016-6210/Openssh 7.2p2 side channel info disclosure POC

    Open source ↗
  • GitHub checkerAlisha-chaudhary/ssh-enum
    Published Apr 30, 2026

    This project explores whether modern OpenSSH reveals valid usernames through subtle response or timing differences. CVE-2016-6210 user enumeration investigation ( Welch's t-test, Cohen's d, and detection engineering ) on a controlled lab on Ubuntu 22.04.5 LTS, it also examines the traces such attempts leave behind and how they can be detected..

    Open source ↗
  • GitHub PoCjustlce/CVE-2016-6210-Exploit
    Published Aug 25, 2019

    OpenSSH Username Enumeration - CVE-2016-6210

    Open source ↗
  • Exploit-DBEDB-40136
    Published Jul 20, 2016

    OpenSSH 7.2p2 - Username Enumeration

    Open source ↗
  • Exploit-DBEDB-40113
    Published Jul 18, 2016

    OpenSSHd 7.2p2 - Username Enumeration

    Open source ↗

Frequently asked(5)

What is CVE-2016-6210?
CVE-2016-6210 is a critical-severity vulnerability; its CVE record was published on February 13, 2017. sshd in OpenSSH before 7.3, when SHA256 or SHA512 are used for user password hashing, uses BLOWFISH hashing on a static password when the username does not exist, which allows remote attackers to enumerate users by leveraging the timing difference between responses when a large password is provided.
When was CVE-2016-6210 made public?
CVE-2016-6210 was made public on July 14, 2016: that is the date its CVE record's CNA, MITRE Corporation, gives for when the vulnerability was made public. The CVE record itself was published on February 13, 2017. EchelonGraph's copy of the record carries a last-modified date of June 17, 2026; the record at its source may have been updated since.
Is CVE-2016-6210 actively exploited?
CVE-2016-6210 is not currently on CISA's Known Exploited Vulnerabilities catalog. EchelonGraph's EG-KEV model places it in Tier 2 (Weaponized), which is not evidence of exploitation: a Metasploit module exists for it, and CISA's SSVC data says a public PoC exists and its EPSS is 50% or more. EchelonGraph does not test whether exploit code works. FIRST EPSS estimates a 89% probability of exploitation in the next 30 days (99th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2016-6210?
CVE-2016-6210 has a CVSS v3 base score of 5.9 (NVD). EchelonGraph synthesises NVD + FIRST EPSS + GHSA into a combined EG score of 9.0 (CRITICAL).
How do I remediate CVE-2016-6210?
A fix for CVE-2016-6210 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2016-6210 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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