CVE-1999-0835
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 · uneditedDenial of service in BIND named via malformed SIG records.
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 confidenceA denial of service vulnerability exists in BIND named DNS server where malformed SIG (signature) records can cause the server to crash or become unresponsive. The vulnerability allows remote attackers to send specially crafted DNS responses containing malformed SIG records to trigger the DoS condition.
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= 4.3= 5= 2= 7= 5.7CVSS 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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Identify if BIND named is runningRun 'ps -ef | grep named' or 'ps -aux | grep named' to check if the named/BIND process is currently active on the systemAffected if named process is not running (not affected)
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Determine BIND versionRun 'named -v' or 'named -V' to display the BIND version, or check the package version using the system's package manager (rpm, pkg, lslpp for AIX)Affected if Version matches affected ranges: IBM AIX 4.3, SCO OpenServer 5, SCO UnixWare 2 or 7, or Sun Solaris 5.7 with BIND vulnerable versions
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Check DNS service exposureReview network configuration: run 'netstat -an | grep :53' or check firewall rules to determine if port 53 (DNS) is listening on external interfacesAffected if DNS service is listening on external/public network interfaces (wider attack surface)
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Verify recursive query configurationCheck the named.conf configuration file for 'allow-recursion' or 'allow-query' directives to see if recursive queries are permitted from untrusted networksAffected if Recursive queries are allowed from any or untrusted networks, making the server vulnerable to crafted responses
The environment is affected if BIND named is running on any of the listed product versions (IBM AIX 4.3, SCO OpenServer 5, SCO UnixWare 2/7, Sun Solaris 5.7) and the DNS service is accessible to network attackers who could send malformed SIG records.
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 a patched version of BIND or migrate to a supported DNS server solution. For legacy systems, consider implementing network-level filtering to block malformed DNS records.
BIND 9.18.x or newer on a supported OS (the affected OS versions AIX 4.3, SunOS 5.7, OpenServer 5, UnixWare 2/7 are all end-of-life)
- 1. Identify the current BIND version installed: `named -v` or `rpm -q bind`
- 2. For the affected legacy systems (AIX 4.3, OpenServer 5, UnixWare 2/7, SunOS 5.7), note these operating systems are end-of-life and no longer receive security updates
- 3. If possible, migrate to a supported operating system that can run modern BIND 9.x
- 4. Install a supported BIND version (BIND 9.18.x or 9.20.x) on the new system
- 5. If migration is not possible, consider implementing network-level filtering to block malformed DNS SIG records
- 6. Use firewall rules to limit DNS traffic to trusted sources only
Generated from the published advisory — verify against the referenced sources before acting.
- 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-1999-0835 — 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-1999-0835 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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