dbcve.org
BindApplication · Isc

CVE-2023-2829

HIGH · 7.5 CVSS v3.1 Published 2023-06-21
Fix available
A fix is available. Upgrade to after 9.18.15 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
A `named` instance configured to run as a DNSSEC-validating recursive resolver with the Aggressive Use of DNSSEC-Validated Cache (RFC 8198) option (`synth-from-dnssec`) enabled can be remotely terminated using a zone with a malformed NSEC record. This issue affects BIND 9 versions 9.16.8-S1 through 9.16.41-S1 and 9.18.11-S1 through 9.18.15-S1.

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 confidence

A remote denial-of-service vulnerability in BIND9 allows an attacker to terminate DNSSEC-validating recursive resolvers configured with the 'synth-from-dnssec' option by sending a malformed NSEC record, causing the named process to crash.

MitigationEither upgrade BIND9 to version 9.16.42-S1/9.18.16-S1 or later, or disable the 'synth-from-dnssec' option in named.conf for affected instances.

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
BindApplication
Affected:>= 9.16.8, <= 9.16.41>= 9.18.11, <= 9.18.15
Active Iq Unified ManagerApplication
Affected:all versions
H500s FirmwareOperating system
Affected:all versions
H700s FirmwareOperating system
Affected:all versions
H410s FirmwareOperating system
Affected:all versions
H410c FirmwareOperating system
Affected:all versions
H300s FirmwareOperating system
Affected:all versions

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. Check BIND9 version
    Run 'named -v' or 'named -V' to determine the installed version of the BIND9 nameserver
    Affected if The version falls within >= 9.16.8 and <= 9.16.41, or >= 9.18.11 and <= 9.18.15
  2. Verify synth-from-dnssec option is enabled
    Search for 'synth-from-dnssec' in named.conf or run 'named-checkconf -z' to parse the configuration and check for this option being set to 'yes' or enabled
    Affected if The 'synth-from-dnssec' option is present and set to 'yes' in the configuration
  3. Confirm DNSSEC validation is active
    Check if 'dnssec-validation' is set to 'yes' or 'auto' in named.conf, or query the running named process for its configuration using 'rndc confgen' or by inspecting the configuration
    Affected if DNSSEC validation is enabled (dnssec-validation is not set to 'no')
  4. Verify recursive resolver is in use
    Check if the server is configured as a recursive resolver by looking for 'recursion yes;' in named.conf and confirming the server handles recursive queries
    Affected if The server is configured as a recursive resolver with recursion enabled

The environment is affected if BIND9 version is within the vulnerable range, the 'synth-from-dnssec' option is enabled, and DNSSEC validation is active on a recursive resolver.

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.

dbcve · scoped
Upgrade available Upgrade to a release after 9.18.15
Interim mitigation

Either upgrade BIND9 to version 9.16.42-S1/9.18.16-S1 or later, or disable the 'synth-from-dnssec' option in named.conf for affected instances.

Recommended fix High confidence

BIND 9.16.42+ or 9.18.16+ (or current stable release 9.18.x/9.16.x beyond affected range)

  1. 1. Identify all BIND named instances in your environment running versions 9.16.8 through 9.16.41 or 9.18.11 through 9.18.15
  2. 2. Check if the `synth-from-dnssec` option is enabled in named.conf (look for `synth-from-dnssec yes;` or default enabled)
  3. 3. If unable to upgrade immediately, disable the `synth-from-dnssec` option by adding `synth-from-dnssec no;` to the `options` block in named.conf as a temporary mitigation
  4. 4. Plan for upgrade during maintenance window
  5. 5. Upgrade BIND to version 9.16.42 or later, or 9.18.16 or later
  6. 6. After upgrade, restart the named service
  7. 7. Verify the named service is running and DNS resolution works correctly
  8. 8. For NetApp products (Active IQ Unified Manager, H-series firmware), consult the NetApp security advisory for product-specific patches
Caveat Review release notes for any configuration or behavior changes between your current version and the upgrade version; test in non-production environment first

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Bind Scoped from the published advisory
  • Consultation2.0 h
  • Implementation3.0 h
  • Testing2.0 h
  • Review / QA1.0 h
8.0 hours of engineering $1,420
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,272.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2023-2829 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2023-2829 in production — separate from our analysis above.

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.

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