CVE-2006-2421
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 · uneditedStack-based buffer overflow in Pragma FortressSSH 4.0.7.20 allows remote attackers to execute arbitrary code via long SSH_MSG_KEXINIT messages, which may cause an overflow when being logged. NOTE: the provenance of this information is unknown; the details are obtained solely from third party information.
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 confidenceStack-based buffer overflow in Pragma FortressSSH 4.0.7.20 allows remote attackers to execute arbitrary code via oversized SSH_MSG_KEXINIT messages that overflow a buffer during logging operations.
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<= 4.0.7.20CVSS 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
- Authentication
- None
- Confidentiality
- Partial
- Integrity
- Partial
- Availability
- Partial
AV:N/AC:L/Au:N/C:P/I:P/A:P
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 checksWork through these to decide whether this CVE applies to you.
-
Confirm FortressSSH installationCheck system for Pragma Systems FortressSSH installation. Look for the SSH service named 'FortressSSH' or 'sshd' from Pragma Systems in Windows Services, or check Program Files for FortressSSH directory.Affected if The software is installed on the system
-
Identify installed versionRun 'ssh -V' or check the version information of the FortressSSH executable/service. On Windows, right-click the ssh.exe binary and select Properties > Details to view the File Version.Affected if The version is 4.0.7.20 or any earlier version (any version <= 4.0.7.20)
-
Verify SSH service is runningCheck if the FortressSSH service is running. Use 'net start' command or check Windows Services for the SSH service from Pragma Systems.Affected if The vulnerable service is actively running and accepting connections
-
Check for signs of exploitation in logsReview FortressSSH log files for异常 or malformed SSH protocol messages, particularly during the key exchange phase. Look for unusually large or truncated entries in SSH_MSG_KEXINIT handling logs.Affected if Logs contain oversized SSH_MSG_KEXINIT messages or evidence of buffer overflow attempts
If Pragma Systems FortressSSH version 4.0.7.20 or earlier is installed and running as an SSH service, the environment is affected by this vulnerability.
Generated from the published advisory. Verify against your own configuration.
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 dataUpgrade to a patched version of FortressSSH; if no update is available, migrate to a maintained SSH server implementation and review logs for indicators of exploitation attempts.
- Consultation3.0 h
- Implementation6.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,224.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2006-2421 — 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 sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2006-2421 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
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.
- 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