CVE-2016-6210

medium

Published 2017-02-13 · Modified 2026-05-29

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CVSS v3

5.9

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS v4 NEW

—

not yet in upstream

VIR risk

6.9

Description

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.

Predictions

Exploit likelihood

100%

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 with source_tier=community-verified.

Exploits

Public proof-of-concept code below. AS-IS, for defenders and authorised testing only.

Metasploit modules

auxiliary_scanner/ssh/ssh_enumusers rank 300

SSH Username Enumeration

Source fetch failed: fetch_error — view the original via the link above.

OS impact

OS	Version	Status	Fixed in
sles		affected
debian	bookworm	fixed	`1:7.2p2-6`
debian	bullseye	fixed	`1:7.2p2-6`
debian	forky	fixed	`1:7.2p2-6`
debian	sid	fixed	`1:7.2p2-6`
debian	trixie	fixed	`1:7.2p2-6`

Application impact

Vendor	Product	Versions	Fixed
openbsd	openssh	`{"endIncluding":"7.2"}`

References

CWEs

CWE-200

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.