FedoraOperating system · Fedoraproject
CVE-2017-9104
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 issue was discovered in adns before 1.5.2. It hangs, eating CPU, if a compression pointer loop is encountered.
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 confidenceadns before 1.5.2 contains a denial-of-service vulnerability where processing a DNS response with a compression pointer loop (malformed packet where DNS name pointers create an infinite cycle) causes the library to hang in an infinite loop, consuming 100% CPU.
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
FedoraOperating system
= 31= 32< 1.5.2= 15.1CVSS 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
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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.
-
Check if adns is installedOn Fedora/RHEL: rpm -qa | grep -i adns. On openSUSE: rpm -qa | grep -i adns. Or check for library files: ls /usr/lib*/libadns*Affected if adns package or library file exists on the system
-
Determine installed adns versionOn Fedora/RHEL: rpm -q adns. On openSUSE: rpm -q adns. Or: adnsresfilter -v 2>&1 || adnscc-cc -v 2>&1Affected if version shown is before 1.5.2 (e.g., 1.5.0, 1.4.0, etc.) or no version is returned but package is present
-
Identify applications using adns for DNS resolutionCheck running processes: ps aux | grep -E 'adns|resolv|bind|unbound' or check linked libraries: lsof +c 0 2>/dev/null | grep libadnsAffected if any application is actively using the adns library to process DNS queries
-
Verify DNS resolver configuration points to adns-enabled serviceCheck /etc/resolv.conf or application configs for nameserver settings, or inspect service configs that use adns (like msmtp, dovecot, postfix if they use adns)Affected if services are configured to use adns for DNS resolution
System is affected if adns library version is present and is below 1.5.2, AND any service or application actively uses it to process DNS responses.
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 · scoped1.5.2
Upgrade adns to version 1.5.2 or later which adds proper detection and handling of compression pointer loops.
adns 1.5.2 or later
- Check the current version of adns installed: `rpm -qa | grep adns` or `dpkg -l | grep adns`
- For Fedora 31/32: Run `sudo dnf update adns` to upgrade to the fixed version
- For openSUSE Leap 15.1: Run `sudo zypper update adns` to upgrade to the fixed version
- For other distributions: Upgrade to adns version 1.5.2 or later from the upstream source at www.chiark.greenend.org.uk
- After upgrading, restart any applications or services that rely on adns to ensure the patched version is loaded
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Fedora
Scoped from the published advisory
- Consultation1.0 h
- Implementation1.0 h
- Testing1.0 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 $1,200.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2017-9104 — 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-2017-9104 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
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.
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
- No spam, self-promotion, credentials, or personal data