OpensshApplication · OpenBSD

CVE-2010-5107

HIGH · 7.5 CVSS v3.1 Published 2013-03-07
Fix available
A fix is available. Upgrade to after 6.1 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
The default configuration of OpenSSH through 6.1 enforces a fixed time limit between establishing a TCP connection and completing a login, which makes it easier for remote attackers to cause a denial of service (connection-slot exhaustion) by periodically making many new TCP connections.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

OpenSSH through version 6.1 enforced a fixed time limit between establishing a TCP connection and completing login in its default configuration. This design allowed remote attackers to cause denial of service by exhausting available connection slots through periodic rapid TCP connection attempts, since connections remained allocated during the login window.

MitigationUpdate OpenSSH to a version beyond 6.1 and configure MaxStartups to limit concurrent unauthenticated connections, or implement rate-limiting at the firewall level to mitigate connection-slot exhaustion.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
OpensshApplication
Affected:<= 6.1= 1.2= 1.2.1= 1.2.2= 1.2.3= 1.2.27= 1.3= 1.5= 1.5.7= 1.5.8= 2.1= 2.1.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify OpenSSH version
    Run 'sshd -v' or 'ssh -V' to obtain the installed OpenSSH version
    Affected if Version is 6.1 or lower, or matches one of the specific affected versions listed (1.2, 1.2.1, 1.2.2, 1.2.3, 1.2.27, 1.3, 1.5, 1.5.7, 1.5.8, 2.1, 2.1.1)
  2. Confirm OpenSSH server is running
    Check for running sshd processes using 'ps aux | grep sshd' or check network listening on port 22
    Affected if OpenSSH server is actively accepting connections and the version is within the affected range
  3. Check if default login time window configuration applies
    Examine the sshd configuration file (typically /etc/ssh/sshd_config) for LoginGraceTime setting - if unset or using default, connections remain allocated during the login window
    Affected if LoginGraceTime is not explicitly configured, indicating default behavior where connections stay allocated for the full login window period
  4. Verify MaxStartups configuration
    Inspect sshd configuration for MaxStartups directive - this setting controls concurrent unauthenticated connections
    Affected if MaxStartups is not configured or is set to a high value, meaning no limit is enforced on concurrent connection slots vulnerable to exhaustion

A system is affected if it runs OpenSSH version 6.1 or lower and relies on default configuration without explicit limits on concurrent unauthenticated connections.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Upgrade available Upgrade to a release after 6.1
Interim mitigation

Update OpenSSH to a version beyond 6.1 and configure MaxStartups to limit concurrent unauthenticated connections, or implement rate-limiting at the firewall level to mitigate connection-slot exhaustion.

Fix this in Openssh Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,240
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,984.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2010-5107 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2010-5107 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data