CVE-2020-10772
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 · uneditedAn incomplete fix for CVE-2020-12662 was shipped for Unbound in Red Hat Enterprise Linux 7, as part of erratum RHSA-2020:2414. Vulnerable versions of Unbound could still amplify an incoming query into a large number of queries directed to a target, even with a lower amplification ratio compared to versions of Unbound that shipped before the mentioned erratum. This issue is about the incomplete fix for CVE-2020-12662, and it does not affect upstream versions of Unbound.
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 confidenceThis is an incomplete fix for CVE-2020-12662 in Red Hat Enterprise Linux 7's packaged version of Unbound DNS server. Despite the RHSA-2020:2414 erratum, vulnerable Unbound versions on RHEL 7 could still perform DNS amplification attacks, converting small incoming queries into a larger number of queries directed at a target victim. The amplification ratio was reduced but not eliminated.
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= 1.6.6-5CVSS 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 checksWork through these to decide whether this CVE applies to you.
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Check if Unbound package is installedRun 'rpm -qa | grep -i unbound' to list installed Unbound packagesAffected if No Unbound package is installed, then not affected; if installed, note the version for next check
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Verify the exact package versionRun 'rpm -qi unbound' or 'rpm -qa unbound*' to get the precise version and release numberAffected if Version is exactly 1.6.6-5 on RHEL 7, indicating the vulnerable package from the original RHSA-2020:2414 erratum
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Check if Unbound service is runningRun 'systemctl status unbound' or 'service unbound status' to determine if the DNS server is activeAffected if Unbound is not running or not enabled, the amplification vector is not active even if the vulnerable version is installed
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Confirm Unbound is configured as an operational DNS resolverInspect /etc/unbound/unbound.conf for 'interface:' directives and 'access-control:' settings that enable recursive DNS queries from clientsAffected if Unbound is configured to accept and process recursive DNS queries from network clients, which is required for the amplification attack to be exploitable
User is affected if Unbound version 1.6.6-5 from RHEL 7 is installed, the unbound service is running, and it is configured to handle recursive DNS queries from network clients.
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 dataOrganizations on RHEL 7 running Unbound should apply all subsequent security errata beyond RHSA-2020:2414, or migrate to upstream Unbound versions which are not affected by this flaw.
- Consultation4.0 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 $4,544.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-10772 — 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-2020-10772 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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