FreeBSDOperating system
CVE-2001-1034
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 · uneditedFormat string vulnerability in Hylafax on FreeBSD allows local users to execute arbitrary code via format specifiers in the -h hostname argument for (1) faxrm or (2) faxalter.
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 · high confidenceFormat string vulnerability in Hylafax allows local users to execute arbitrary code by providing format specifiers in the -h hostname argument to faxrm or faxalter commands. The vulnerability stems from passing user-controlled input directly to printf-style functions without proper format string sanitization, enabling stack manipulation.
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
FreeBSDOperating system
= 4.4CVSS 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
- Local
- Complexity
- Low
- Authentication
- None
- Confidentiality
- Complete
- Integrity
- Complete
- Availability
- Complete
AV:L/AC:L/Au:N/C:C/I:C/A:C
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.
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Check if Hylafax is installedLocate the faxrm and faxalter binaries on the system using 'which faxrm faxalter' or 'find /usr -name faxrm -o -name faxalter'Affected if Either faxrm or faxalter binary exists on the system
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Check the FreeBSD versionRun 'uname -r' or check /etc/osrelease for FreeBSD version informationAffected if FreeBSD version equals 4.4 (exact match)
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Verify Hylafax package versionCheck the installed Hylafax version using 'pkg_info | grep hylafax' or 'rpm -q hylafax' if applicableAffected if Hylafax version matches the vulnerable release tied to FreeBSD 4.4
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Check ownership and permissions on vulnerable binariesRun 'ls -la /usr/bin/faxrm /usr/bin/faxalter' (or the actual paths found) to inspect permissionsAffected if Binaries are owned by root and world-executable, allowing untrusted local users to execute them
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Verify local user access to faxrm/faxalterCheck which local users have access to the faxrm/faxalter commands using 'getent group fax' or by reviewing binary execute permissionsAffected if Untrusted local users can execute faxrm or faxalter with the -h argument
A system is affected if it runs FreeBSD 4.4 with Hylafax installed and the faxrm/faxalter binaries are accessible to untrusted local users who can supply format specifiers to the -h hostname argument.
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 Hylafax or apply vendor-supplied patches. If upgrading is not feasible, restrict local access to faxrm and faxalter commands via file permissions to prevent untrusted local users from exploiting the vulnerability.
Fix this in FreeBSD
Scoped from the published advisory
- Consultation2.0 h
- Implementation1.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,696.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2001-1034 — 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-2001-1034 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
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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
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