FedoraOperating system · Fedoraproject
CVE-2021-3445
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 · uneditedA flaw was found in libdnf's signature verification functionality in versions before 0.60.1. This flaw allows an attacker to achieve code execution if they can alter the header information of an RPM package and then trick a user or system into installing it. The highest risk of this vulnerability is to confidentiality, integrity, as well as system availability.
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 confidenceA signature verification bypass exists in libdnf versions before 0.60.1 where the header information of an RPM package can be altered without detection, allowing an attacker to inject malicious content and achieve arbitrary code execution upon package installation.
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
= 33= 34
Enterprise LinuxOperating system
= 8.0< 0.60.1CVSS 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
- High
- Privileges
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/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.
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Identify installed libdnf versionRun 'rpm -q libdnf' or 'dnf info libdnf' to retrieve the currently installed version numberAffected if Version is lower than 0.60.1 (for example, 0.55.x, 0.56.x, 0.57.x, 0.58.x, or 0.59.x)
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Confirm operating system versionRun 'cat /etc/os-release' or 'hostnamectl' to identify the distribution and versionAffected if System is Fedora 33, Fedora 34, or Red Hat Enterprise Linux 8.0
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Verify RPM signature verification statusRun 'rpm --query --all --queryformat "%{NAME} %{SIGPGP:hex}" | head' to check if packages have signature metadata presentAffected if RPM signature verification is configured but the library fails to validate header integrity properly (this requires manual testing or code review to confirm the bypass condition)
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Check libdnf library fileRun 'rpm -ql libdnf | grep -E "\.so"' to locate the shared library and verify the build version string within the binary if neededAffected if The linked library version matches a vulnerable release
A system is affected if it runs Fedora 33, Fedora 34, RHEL 8.0, or any libdnf version prior to 0.60.1, and relies on libdnf for RPM package management with signature verification enabled.
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 data0.60.1
Upgrade libdnf to version 0.60.1 or later. Verify all RPM package signature verifications are functioning correctly after the update.
Fix this in Fedora
Scoped from the published advisory
- Consultation2.0 h
- Implementation2.0 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 $2,752.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-3445 — 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-2021-3445 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
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