LinuxOperating system · Redhat
CVE-1999-0009
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 · uneditedInverse query buffer overflow in BIND 4.9 and BIND 8 Releases.
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 confidenceBuffer overflow vulnerability in BIND 4.9 and BIND 8 DNS server implementations, specifically in the inverse query handling code. This memory corruption flaw could allow remote attackers to execute arbitrary code or cause a denial of service via specially crafted inverse DNS queries.
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
LinuxOperating system
= 4.0= 4.1= 4.2= 5.0= 5.4_3.0= 5.4_3.1= 5.4_4.1= 5.4_4.11= 4.9.6= 8.1= 8.1.1= 3.2= 3.3= 3.3.1= 3.3.2= 3.3.3= 4.0= 4.0.1= 4.0.1t= 4.0.2= 4.0.3= 4.0.4= 4.0.4b= 2.0= 2.0.1= 2.1= 1.0= 4.1= 4.1.1= 4.1.2= 4.1.3= 4.1.4= 4.1.5= 4.2= 4.2.1= 4.3= 64CVSS 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
- Complete
- Integrity
- Complete
- Availability
- Complete
AV:N/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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Confirm BIND named process is runningRun 'ps -ef | grep named' or 'ps -aux | grep named' to check if the BIND DNS server process is active on the system.Affected if No named process found means the system is not running BIND and is not affected by this specific vulnerability.
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Identify installed BIND versionRun 'named -v' or 'named -V' to display the BIND version. On Red Hat systems, also check '/usr/sbin/named -v'. For RPM-based systems, use 'rpm -q bind' to query the package version.Affected if The system is potentially affected if the version matches BIND 4.9.6, 8.1, or 8.1.1, or if the underlying OS version (Red Hat 4.0-5.0, SGI IRIX 3.2-4.0.4b, BSDi 2.0-2.1, IBM AIX 4.1-4.3, etc.) shipped with these vulnerable BIND versions.
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Verify inverse query handling is enabledCheck the BIND configuration file (typically '/etc/named.conf' for BIND 8 or '/etc/named.boot' for BIND 4) for any 'options' or 'zone' directives that control inverse query processing. Inverse queries (PTR records for IP-to-name resolution) are handled by default in vulnerable versions.Affected if If BIND 4.9.x or 8.x is running and configured to handle DNS queries, inverse query processing is active by default and the vulnerability is exploitable.
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Check network exposure of DNS serviceReview firewall rules (iptables -L -n on Linux, netstat -tulpn | grep :53) to determine if UDP/TCP port 53 is exposed to untrusted networks. Also examine '/etc/hosts.allow' and '/etc/hosts.deny' for TCP wrapper restrictions on named.Affected if If the DNS service is accessible from untrusted networks (0.0.0.0/0 or external interfaces without firewall filtering), the system is at risk of remote exploitation.
A system is affected if it runs BIND 4.9.6, 8.1, or 8.1.1 (or an OS that shipped these versions) with DNS service exposed to the network, as the inverse query buffer overflow can be triggered remotely.
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.
dbcve · scopedUpgrade to patched versions of BIND 8.2.x or later, or migrate to modern supported DNS server implementations such as current BIND9 or alternative DNS software. If BIND 4.9/8 systems remain in production, isolate them from untrusted networks immediately.
BIND 4.9.7+ or BIND 8.2+ (preferred: BIND 9.x stable branch)
- 1. Identify the current BIND version installed by running 'named -v' or 'named -V'
- 2. If running BIND 4.9.6, upgrade to BIND 4.9.7 or later in the 4.9.x stable series
- 3. If running BIND 8.1 or 8.1.1, upgrade to BIND 8.2 or later in the 8.x stable series
- 4. Alternatively, upgrade to BIND 9.x (modern stable branch) which is not affected by this vulnerability
- 5. After upgrading, verify the new version is running: 'named -v'
- 6. Test DNS functionality to ensure the server is responding correctly to queries
- 7. Review configuration files for any needed adjustments for the new BIND version
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Linux
Scoped from the published advisory
- Consultation2.0 h
- Implementation8.0 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 $4,480.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-1999-0009 — 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-1999-0009 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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- 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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