CVE-2016-6210

Exp

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.

Published: 2017-02-13 Last update: 2026-05-29 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2016-6210 is rated High Exploit Risk (71/100): CVSS Medium severity, with high exploitation likelihood (EPSS 90.05%, 100th percentile). 2 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2016-6210

EDB-ID Source Kind Published Link
40136 exploit_db edb 2016-07-20 Exploit-DB ↗
40113 exploit_db edb 2016-07-18 Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2016-6210

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-22 92.49% 90.05% -2.44%
2 2026-03-04 92.27% 92.49% +0.21%
3 2026-03-01 — 92.27% —

Full EPSS history (40 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2016-6210

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.9 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 2.2 3.6 134c704f-9b21-4f2e-91b3-4a467353bcc0
5.9 3.0 MEDIUM
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 2.2 3.6 [email protected]
4.3 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:N/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 8.6 2.9 [email protected]

Weakness enumeration for CVE-2016-6210

OS Trackers for CVE-2016-6210

vendor priority summary link
debian not yet assigned CVE-2016-6210 not yet assigned priority: Debian including 1 source packages (openssh), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2016-6210
gentoo normal CVE-2016-6210: 1 GLSA(s) (201612-18), 1 atom(s) (net-misc/openssh); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2016-6210
redhat medium — https://access.redhat.com/security/cve/CVE-2016-6210
suse medium CVE-2016-6210 severity moderate: SUSE including 355 source package names (amazon/suse-sles-15-sp1-chost-byos-v20210304-hvm-ssd-x86_64, amazon/suse-sles-15-sp1-chost-byos-v20220127-hvm-ssd-x86_64, …), 456 product×package rows across 66 product lines (HPE Helion OpenStack 8, SUSE Liberty Linux 7, … (66 product lines)): Fixed 264, Known Affected 157, Known Not Affected 35. https://www.suse.com/security/cve/CVE-2016-6210/
ubuntu low CVE-2016-6210 low priority: Ubuntu including 1 source packages (openssh), 7 status rows across 7 suites (precise, trusty, upstream, wily, xenial, yakkety, zesty): released 4, not-affected 2, ignored 1. https://ubuntu.com/security/CVE-2016-6210

Affected software / configurations for CVE-2016-6210

Vendor Product Version Raw CPE
openbsd openssh <= 7.2 cpe:2.3:a:openbsd:openssh:*:p2:*:*:*:*:*:*

References for CVE-2016-6210

cvelogic Threat Intelligence